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Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow.

  Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for every 10 meters of depth in seawater, so that at 39 meters in seawater a diver is exposed to pressure of about 4 atmospheres. The pressure of the gases being breathed must equal the external pressure applied to the body, otherwise breathing is very difficult. Therefore all of the gases in the air breathed by a scuba diver at 40 meter are present at five times their usual pressure. Nitrogen, which composes 80 percent of the air we breathe, usually causes a balmy feeling of well-being at this pressure. At a depth of 5 atmospheres, nitrogen causes symptoms resembling alcohol intoxication, known as nitrogen narcosis. Nitrogen narcosis apparently results from a direct effect on the brain of the large amounts of nitrogen dissolved in the blood. Deep dives are less dangerous if helium is substituted for nitrogen, because under these pressures helium does not exert a similar narcotic effect.

  As a scuba diver descends, the pressure of nitrogen on the lungs increases. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues The reverse occurs when the diver surfaces, the nitrogen pressure in the lungs falls and the nitrogen diffuses from the tissues into the blood, and from the blood into the lungs. If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed. They can cause severe pains, particularly around the joints.

  Another complication may result if the breath is held during ascent. During ascent from a depth of 10 meters, the volume of air in the lungs will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism.

  To avoid this event, a diver must ascend slowly, never at a rate exceeding the rise of the exhaled air bubbles, and must exhale during ascent.

The word “exert” in bold in paragraph 1 is closest in meaning to _________.

A. cause

B. permit

C. change

D. need

1
10 tháng 9 2018

Chọn A

Từ "exert" in đậm ở đoạn 1 gần nghĩa nhất với________.

A. gây ra

B. cho phép

C. thay đổi

D. cần

exert (v) = cause (v): gây

Dịch câu: Những thợ lặn sâu thường ít nguy hiểm hơn nếu khi Heli được thay thế cho khí Nitơ, bởi vì dưới áp lực, khí heli không gây ra tác dụng gây mê tương tự.

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow.   Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow.

  Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for every 10 meters of depth in seawater, so that at 39 meters in seawater a diver is exposed to pressure of about 4 atmospheres. The pressure of the gases being breathed must equal the external pressure applied to the body, otherwise breathing is very difficult. Therefore all of the gases in the air breathed by a scuba diver at 40 meter are present at five times their usual pressure. Nitrogen, which composes 80 percent of the air we breathe, usually causes a balmy feeling of well-being at this pressure. At a depth of 5 atmospheres, nitrogen causes symptoms resembling alcohol intoxication, known as nitrogen narcosis. Nitrogen narcosis apparently results from a direct effect on the brain of the large amounts of nitrogen dissolved in the blood. Deep dives are less dangerous if helium is substituted for nitrogen, because under these pressures helium does not exert a similar narcotic effect.

  As a scuba diver descends, the pressure of nitrogen on the lungs increases. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues The reverse occurs when the diver surfaces, the nitrogen pressure in the lungs falls and the nitrogen diffuses from the tissues into the blood, and from the blood into the lungs. If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed. They can cause severe pains, particularly around the joints.

  Another complication may result if the breath is held during ascent. During ascent from a depth of 10 meters, the volume of air in the lungs will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism.

  To avoid this event, a diver must ascend slowly, never at a rate exceeding the rise of the exhaled air bubbles, and must exhale during ascent.

What does the passage mainly discuss?

A. How to prepare for a deep dive 

B. The effect of pressure on gases in the human body. 

C. The equipment divers use 

D. The symptoms of nitrogen bubbles in the bloodstream

1
10 tháng 8 2019

Chọn B

Bài đọc chủ yếu thảo luận về vấn đề gì?

A. How to prepare for a deep dive: Cách chuẩn bị cho một chuyến lặn sâu

B. The effects of pressure on gases in the human body: Tác động của áp lực lên không khí trong cơ thể con người.

C. The equipment divers use: Thiết bị mà thợ lặn sử dụng

D. The symptoms of nitrogen bubbles in the bloodstream: Dấu hiệu khi bóng Ni tơ ở trong dòng chảy của máu.

Dẫn chứng: “Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure” (Trong một số trường hợp nhất định, cơ thể con người phải đối phó với các khí ở áp suất khí quyển lớn hơn bình thường)

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow. Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow.

Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for every 10 meters of depth in seawater, so that at 39 meters in seawater a diver is exposed to pressure of about 4 atmospheres. The pressure of the gases being breathed must equal the external pressure applied to the body, otherwise breathing is very difficult. Therefore all of the gases in the air breathed by a scuba diver at 40 meter are present at five times their usual pressure. Nitrogen, which composes 80 percent of the air we breathe, usually causes a balmy feeling of well-being at this pressure. At a depth of 5 atmospheres, nitrogen causes symptoms resembling alcohol intoxication, known as nitrogen narcosis. Nitrogen narcosis apparently results from a direct effect on the brain of the large amounts of nitrogen dissolved in the blood. Deep dives are less dangerous if helium is substituted for nitrogen, because under these pressures helium does not exert a similar narcotic effect.

As a scuba diver descends, the pressure of nitrogen on the lungs increases. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues The reverse occurs when the diver surfaces, the nitrogen pressure in the lungs falls and the nitrogen diffuses from the tissues into the blood, and from the blood into the lungs. If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed. They can cause severe pains, particularly around the joints.

Another complication may result if the breath is held during ascent. During ascent from a depth of 10 meters, the volume of air in the lungs will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism.

To avoid this event, a diver must ascend slowly, never at a rate exceeding the rise of the exhaled air bubbles, and must exhale during ascent.

 

What does the passage mainly discuss?

A. How to prepare for a deep dive

B. The effect of pressure on gases in the human body

C. The equipment divers use

D. The symptoms of nitrogen bubbles in the bloodstream

1
30 tháng 6 2017

Đáp án B

Bài đọc chủ yếu thảo luận về vấn đề gì?

A. How to prepare for a deep dive: Cách chuẩn bị cho một chuyến lặn sâu

B. The effects of pressure on gases in the human body: Tác động của áp lực lên không khí trong cơ thể con người.

C. The equipment divers use: Thiết bị mà thợ lặn sử dụng

D. The symptoms of nitrogen bubbles in the bloodstream: Dấu hiệu khi bóng Ni tơ ở trong dòng chảy của máu.

Thông tin ở câu chủ đề của đoạn: “Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure” (Trong một số trường hợp nhất định, cơ thể con người phải đối phó với các khí ở áp suất khí quyển lớn hơn bình thường)

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow. Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow.

Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for every 10 meters of depth in seawater, so that at 39 meters in seawater a diver is exposed to pressure of about 4 atmospheres. The pressure of the gases being breathed must equal the external pressure applied to the body, otherwise breathing is very difficult. Therefore all of the gases in the air breathed by a scuba diver at 40 meter are present at five times their usual pressure. Nitrogen, which composes 80 percent of the air we breathe, usually causes a balmy feeling of well-being at this pressure. At a depth of 5 atmospheres, nitrogen causes symptoms resembling alcohol intoxication, known as nitrogen narcosis. Nitrogen narcosis apparently results from a direct effect on the brain of the large amounts of nitrogen dissolved in the blood. Deep dives are less dangerous if helium is substituted for nitrogen, because under these pressures helium does not exert a similar narcotic effect.

As a scuba diver descends, the pressure of nitrogen on the lungs increases. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues The reverse occurs when the diver surfaces, the nitrogen pressure in the lungs falls and the nitrogen diffuses from the tissues into the blood, and from the blood into the lungs. If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed. They can cause severe pains, particularly around the joints.

Another complication may result if the breath is held during ascent. During ascent from a depth of 10 meters, the volume of air in the lungs will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism.

To avoid this event, a diver must ascend slowly, never at a rate exceeding the rise of the exhaled air bubbles, and must exhale during ascent.

 

It can be inferred from the passage that which of the following presents the greatest danger to a diver?

A. Pressurized helium 

B. Nitrogen diffusion 

C. An air embolism 

D. Nitrogen bubbles 

1
13 tháng 6 2018

Đáp án C

Có thể suy ra từ bài đọc rằng điều gì là mối nguy hiểm lớn nhất đối với thợ lặn?

A. Pressurized helium: Khí Heli nén

B. Nitrogen diffusion: Sự khuếch tán khí Nitơ

C. An air embolism: Sự thuyên tắc hơi

D.Nitrogen bubbles: Bóng khí Nitơ

Thông tin ở đoạn cuối, dòng thứ nhất. “During ascent from a depth of 10 meters, the volume of air in the lung will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism.” (Trong quá trình nồi lên từ độ sâu 10 mét, lượng không khí trong phổi sẽ tăng lên gấp đôi vì áp lực khí tại bề mặt nước chỉ còn 1 nửa so với ở độ sâu 10 mét. Sự thay đổi về lượng khí có thể làm phổi sưng phồng, thậm chí là vỡ nát. Hiện tượng này gọi là thuyên tắc hơi.) 

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow.   Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow.

  Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for every 10 meters of depth in seawater, so that at 39 meters in seawater a diver is exposed to pressure of about 4 atmospheres. The pressure of the gases being breathed must equal the external pressure applied to the body, otherwise breathing is very difficult. Therefore all of the gases in the air breathed by a scuba diver at 40 meter are present at five times their usual pressure. Nitrogen, which composes 80 percent of the air we breathe, usually causes a balmy feeling of well-being at this pressure. At a depth of 5 atmospheres, nitrogen causes symptoms resembling alcohol intoxication, known as nitrogen narcosis. Nitrogen narcosis apparently results from a direct effect on the brain of the large amounts of nitrogen dissolved in the blood. Deep dives are less dangerous if helium is substituted for nitrogen, because under these pressures helium does not exert a similar narcotic effect.

  As a scuba diver descends, the pressure of nitrogen on the lungs increases. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues The reverse occurs when the diver surfaces, the nitrogen pressure in the lungs falls and the nitrogen diffuses from the tissues into the blood, and from the blood into the lungs. If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed. They can cause severe pains, particularly around the joints.

  Another complication may result if the breath is held during ascent. During ascent from a depth of 10 meters, the volume of air in the lungs will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism.

  To avoid this event, a diver must ascend slowly, never at a rate exceeding the rise of the exhaled air bubbles, and must exhale during ascent.

It can be inferred from the passage that which of the following presents the greatest danger to a diver?

A. Pressurized helium

B. Nitrogen diffusion

C. An air embolism

D. Nitrogen bubbles

1
6 tháng 4 2017

Chọn C

Có thể suy ra từ bài đọc rằng điều gì là mối nguy hiểm lớn nhất đối với thợ lặn?

A. Pressurized helium: Khí Heli nén

B. Nitrogen diffusion: Sự khuếch tán khí Nitơ

C. An air embolism: Sự thuyên tắc hơi

D. Nitrogen bubbles: Bóng khí Nitơ

Thông tin ở đoạn cuối, dòng thứ nhất. “During ascent from a depth of 10 meters, the volume of air in the lung will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism.” (Trong quá trình nồi lên từ độ sâu 10 mét, lượng không khí trong phổi sẽ tăng lên gấp đôi vì áp lực khí tại bề mặt nước chỉ còn 1 nửa so với ở độ sâu 10 mét. Sự thay đổi về lượng khí có thể làm phổi sưng phồng, thậm chí là vỡ nát. Hiện tượng này gọi là thuyên tắc hơi.) 

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow.   Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow.

  Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for every 10 meters of depth in seawater, so that at 39 meters in seawater a diver is exposed to pressure of about 4 atmospheres. The pressure of the gases being breathed must equal the external pressure applied to the body, otherwise breathing is very difficult. Therefore all of the gases in the air breathed by a scuba diver at 40 meter are present at five times their usual pressure. Nitrogen, which composes 80 percent of the air we breathe, usually causes a balmy feeling of well-being at this pressure. At a depth of 5 atmospheres, nitrogen causes symptoms resembling alcohol intoxication, known as nitrogen narcosis. Nitrogen narcosis apparently results from a direct effect on the brain of the large amounts of nitrogen dissolved in the blood. Deep dives are less dangerous if helium is substituted for nitrogen, because under these pressures helium does not exert a similar narcotic effect.

  As a scuba diver descends, the pressure of nitrogen on the lungs increases. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues The reverse occurs when the diver surfaces, the nitrogen pressure in the lungs falls and the nitrogen diffuses from the tissues into the blood, and from the blood into the lungs. If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed. They can cause severe pains, particularly around the joints.

  Another complication may result if the breath is held during ascent. During ascent from a depth of 10 meters, the volume of air in the lungs will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism.

  To avoid this event, a diver must ascend slowly, never at a rate exceeding the rise of the exhaled air bubbles, and must exhale during ascent.

What happens to nitrogen in body tissues if a diver ascends too quickly?

A. It forms bubbles

B. It is reabsorbed by the lungs

C. It goes directly to the brain

D. It has a narcotic effect

1
19 tháng 9 2018

Chọn A

 Điều gì xảy ra với ni-tơ trong tế bào cơ thể nếu một thợ lặn giảm quá nhanh?

A. It forms bubbles: Chúng tạo thành bóng khí

B. It is reabsorbed by the lungs: Chúng được phổi hấp thụ lại

C. It goes directly to the brain: Chúng đi thẳng vào não

D. It has narcotic effect: Chúng có tác động gây mê

Thông tin ở đoạn thứ 2, dòng thứ 4. “If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed.” (Nếu như quay trở lại mặt nước quá nhanh, khí ni tơ trong các mô và máu không thể khuếch tan ra ngoài đủ nhanh chóng và bóng khí ni tơ sẽ hình thành.)

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow. Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow.

Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for every 10 meters of depth in seawater, so that at 39 meters in seawater a diver is exposed to pressure of about 4 atmospheres. The pressure of the gases being breathed must equal the external pressure applied to the body, otherwise breathing is very difficult. Therefore all of the gases in the air breathed by a scuba diver at 40 meter are present at five times their usual pressure. Nitrogen, which composes 80 percent of the air we breathe, usually causes a balmy feeling of well-being at this pressure. At a depth of 5 atmospheres, nitrogen causes symptoms resembling alcohol intoxication, known as nitrogen narcosis. Nitrogen narcosis apparently results from a direct effect on the brain of the large amounts of nitrogen dissolved in the blood. Deep dives are less dangerous if helium is substituted for nitrogen, because under these pressures helium does not exert a similar narcotic effect.

As a scuba diver descends, the pressure of nitrogen on the lungs increases. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues The reverse occurs when the diver surfaces, the nitrogen pressure in the lungs falls and the nitrogen diffuses from the tissues into the blood, and from the blood into the lungs. If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed. They can cause severe pains, particularly around the joints.

Another complication may result if the breath is held during ascent. During ascent from a depth of 10 meters, the volume of air in the lungs will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism.

To avoid this event, a diver must ascend slowly, never at a rate exceeding the rise of the exhaled air bubbles, and must exhale during ascent.

 

What happens to nitrogen in body tissues if a diver ascends too quickly?

A. It forms bubbles 

B. It is reabsorbed by the lungs 

C. It goes directly to the brain

D. It has a narcotic effect 

1
29 tháng 12 2018

Đáp án A

Điều gì xảy ra với ni-tơ trong tế bào cơ thể nếu một thợ lặn giảm quá nhanh?

A. It forms bubbles: Chúng tạo thành bóng khí

B. It is reabsorbed by the lungs: Chúng được phổi hấp thụ lại

C. It goes directly to the brain: Chúng đi thẳng vào não

D. It has narcotic effect: Chúng có tác động gây mê

Thông tin ở đoạn thứ 2, dòng thứ 4. “If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed.” (Nếu như quay trở lại mặt nước quá nhanh, khí ni tơ trong các mô và máu không thể khuếch tan ra ngoài đủ nhanh chóng và bóng khí ni tơ sẽ hình thành.)

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow. Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow.

Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for every 10 meters of depth in seawater, so that at 39 meters in seawater a diver is exposed to pressure of about 4 atmospheres. The pressure of the gases being breathed must equal the external pressure applied to the body, otherwise breathing is very difficult. Therefore all of the gases in the air breathed by a scuba diver at 40 meter are present at five times their usual pressure. Nitrogen, which composes 80 percent of the air we breathe, usually causes a balmy feeling of well-being at this pressure. At a depth of 5 atmospheres, nitrogen causes symptoms resembling alcohol intoxication, known as nitrogen narcosis. Nitrogen narcosis apparently results from a direct effect on the brain of the large amounts of nitrogen dissolved in the blood. Deep dives are less dangerous if helium is substituted for nitrogen, because under these pressures helium does not exert a similar narcotic effect.

As a scuba diver descends, the pressure of nitrogen on the lungs increases. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues The reverse occurs when the diver surfaces, the nitrogen pressure in the lungs falls and the nitrogen diffuses from the tissues into the blood, and from the blood into the lungs. If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed. They can cause severe pains, particularly around the joints.

Another complication may result if the breath is held during ascent. During ascent from a depth of 10 meters, the volume of air in the lungs will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism.

To avoid this event, a diver must ascend slowly, never at a rate exceeding the rise of the exhaled air bubbles, and must exhale during ascent.

 

The word “exert” in bold in paragraph 1 is closest in meaning to ________.

A. cause 

B. permit 

C. change 

D. need 

1
25 tháng 3 2018

Đáp án A

Từ "exert" in đậm ở đoạn 1 gần nghĩa nhất với________.

A. gây ra

B. cho phép

C. thay đổi

D. cần

exert (v) = cause (v) : gây

Dịch nghĩa : Những thợ lặn sâu thường ít nguy hiểm hơn nếu khi Heli được thay thế cho khí Nitơ, bởi vì dưới áp lực, khí heli không gây ra tác dụng gây mê tương tự.

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow. Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow.

Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for every 10 meters of depth in seawater, so that at 39 meters in seawater a diver is exposed to pressure of about 4 atmospheres. The pressure of the gases being breathed must equal the external pressure applied to the body, otherwise breathing is very difficult. Therefore all of the gases in the air breathed by a scuba diver at 40 meter are present at five times their usual pressure. Nitrogen, which composes 80 percent of the air we breathe, usually causes a balmy feeling of well-being at this pressure. At a depth of 5 atmospheres, nitrogen causes symptoms resembling alcohol intoxication, known as nitrogen narcosis. Nitrogen narcosis apparently results from a direct effect on the brain of the large amounts of nitrogen dissolved in the blood. Deep dives are less dangerous if helium is substituted for nitrogen, because under these pressures helium does not exert a similar narcotic effect.

As a scuba diver descends, the pressure of nitrogen on the lungs increases. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues The reverse occurs when the diver surfaces, the nitrogen pressure in the lungs falls and the nitrogen diffuses from the tissues into the blood, and from the blood into the lungs. If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed. They can cause severe pains, particularly around the joints.

Another complication may result if the breath is held during ascent. During ascent from a depth of 10 meters, the volume of air in the lungs will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism.

To avoid this event, a diver must ascend slowly, never at a rate exceeding the rise of the exhaled air bubbles, and must exhale during ascent.

 

The word “rupture” in bold in paragraph 3 is closest in meaning to ________.

A. hurt

B. shrink 

C. burst 

D. stop 

1
3 tháng 9 2018

Đáp án C

Từ “ rupute” được in đậm ở đoạn 3 gần nghĩa nhất với ________.

A. Hurt: đau

B. Shrink: co lại

C. Burst: vỡ, nổ, bục ra

D. Stop: dừng lại

Rupute: vỡ nát = burst

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow.   Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for...
Đọc tiếp

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the questions that follow.

  Under certain circumstances, the human body must cope with gases at greater-than-normal atmospheric pressure. For example, gas pressures increase rapidly during a drive made with scuba gear because the breathing equipment allows divers to stay underwater longer and dive deeper. The pressure exerted on the human body increases by 1 atmosphere for every 10 meters of depth in seawater, so that at 39 meters in seawater a diver is exposed to pressure of about 4 atmospheres. The pressure of the gases being breathed must equal the external pressure applied to the body, otherwise breathing is very difficult. Therefore all of the gases in the air breathed by a scuba diver at 40 meter are present at five times their usual pressure. Nitrogen, which composes 80 percent of the air we breathe, usually causes a balmy feeling of well-being at this pressure. At a depth of 5 atmospheres, nitrogen causes symptoms resembling alcohol intoxication, known as nitrogen narcosis. Nitrogen narcosis apparently results from a direct effect on the brain of the large amounts of nitrogen dissolved in the blood. Deep dives are less dangerous if helium is substituted for nitrogen, because under these pressures helium does not exert a similar narcotic effect.

  As a scuba diver descends, the pressure of nitrogen on the lungs increases. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues. Nitrogen then diffuses from the lungs to the blood, and from the blood to body tissues The reverse occurs when the diver surfaces, the nitrogen pressure in the lungs falls and the nitrogen diffuses from the tissues into the blood, and from the blood into the lungs. If the return to the surface is too rapid, nitrogen in the tissues and blood cannot diffuse out rapidly enough and nitrogen bubbles are formed. They can cause severe pains, particularly around the joints.

  Another complication may result if the breath is held during ascent. During ascent from a depth of 10 meters, the volume of air in the lungs will double because the air pressure at the surface is only half of what it was at 10 meters. This change in volume may cause the lungs to distend and even rupture. This condition is called air embolism.

  To avoid this event, a diver must ascend slowly, never at a rate exceeding the rise of the exhaled air bubbles, and must exhale during ascent.

The word “rupture in bold in paragraph 3 is closest in meaning to _________.

A. shrink

B. burst 

C. hurt

D. stop

1
12 tháng 6 2017

Chọn B  

Từ “rupture” in đậm trong đoạn 3 đồng nghĩa với____

A. Co vào

B. Vỡ

C. Tổn thương

B. dừng

Dịch bài:

Trong một số trường hợp nhất định, cơ thể con người phải đối phó với các khí ở áp suất khí quyển lớn hơn bình thường. Chẳng hạn, áp suất khí tăng lên nhanh chóng trong khi lặn bằng thiết bị lặn bởi vì thiết bị thở cho phép thợ lặn ở dưới nước lâu hơn và lặn sâu hơn. Áp lực tác động lên cơ thể con người tăng lên 1 atmôtfe cho mỗi 10 mét chiều sâu trong nước biển, do đó ở 39 mét trong nước biển thợ lặn phải chịu áp lực khoảng 4 atmôtfe. Do đó tất cả các khí trong không khí hít thở của một thợ lặn bình thường ở độ cao 40 mét phải ở mức gấp năm lần áp suất thông thường của chúng. Nitơ, chiếm 80% không khí chúng ta hít vào, thường tạo ra cảm giác thoải mái khi chịu áp lực này. Ở độ sâu 5 ô, nitơ gây ra các triệu chứng giống như say rượu, được gọi là nhiễm độc nitơ. Nôn mửa nitơ dường như là kết quả từ một ảnh hưởng trực tiếp đến bộ não của một lượng lớn nitơ hòa tan trong máu. Những thợ lặn sâu thường ít nguy hiểm hơn nếu khi Heli được thay thế cho khí Nitơ, bởi vì dưới áp lực, khí heli không gây ra tác dụng gây mê tương tự.

Khi một thợ lặn lặn xuống, áp lực của nitơ lên phổi tăng lên. Nitơ sau đó phân tán từ phổi sang máu, và từ máu đến các mô cơ thể. Quá trình ngược lại xảy ra khi các thợ lặn trở lên mặt nước, áp suất nitơ trong phổi hạ xuống và nitơ khuếch tán từ mô vào máu, và từ máu vào phổi . Nếu như quay trở lại mặt nước quá nhanh, khí ni tơ trong các mô và máu không thể khuếch tán ra ngoài đủ nhanh chóng và bóng khí ni tơ sẽ hình thành. Nếu như quay trở lại mặt nước quá nhanh, khí ni tơ trong các mô và máu không thể khuếch tan ra ngoài đủ nhanh chóng và bóng khí ni tơ sẽ hình thành. Chúng sẽ gây ra những cơn đau khủng khiếp, đặc biệt là xung quanh các khớp xương.

Một biến chứng khác có thể xảy ra nếu hơi thở được giữ trong quá trình trở lên mặt nước. Trong quá trình nồi lên từ độ sâu 10 mét, lượng không khí trong phổi sẽ tăng lên gấp đôi vì áp lực khí tại bề mặt nước chỉ còn 1 nửa so với ở độ sâu 10 mét. Sự thay đổi về lượng khí có thể làm phổi sưng phồng, thậm chí là vỡ nát. Hiện tượng này gọi là thuyên tắc hơi.

Để tránh sự hiện tượng này, một thợ lặn phải đi nổi lên thật chậm, không bao giờ ở tốc độ vượt quá sự nổi lên của bong bóng khí thở ra, và phải thở ra khi lên.