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

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 from 38 to 42.

(1) Though Edmund Halley was most famous because of his achievements as an astronomer, he was a scientist of diverse interests and great skill. In addition to studying the skies, Halley was also deeply interested in exploring the unknown depths of the oceans. One of his lesser-known accomplishments that were quite remarkable was his design for a diving bell that facilitated exploration of the watery depths.

(2) The diving bell that Halley designed had a major advantage over the diving bells that were in use prior to his. Earlier diving bells could only make use of the air contained within the bell itself, so divers had to surface when the air inside the bell ran low. Halley’s bell was an improvement in that its design allowed for an additional supply of fresh air that enabled a crew of divers to remain underwater for several hours.

(3) The diving contraption that Halley designed was in the shape of a bell that measured three feet across the top and five feet across the bottom and could hold several divers comfortably; it was open at the bottom so that divers could swim in and out at will. The bell was built of wood, which was first heavily tarred to make it water repellent and was then covered with a half-ton sheet of lead to make the bell heavy enough to sink in water. The bell shape held air inside for the divers to breathe as the bell sank to the bottom.

(4) The air inside the bell was not the only source of air for the divers to breathe, and it was this improvement that made Halley’s bell superior to its predecessors. In addition to the air already in the bell, air was also supplied to the divers from a lead barrel that was lowered to the ocean floor close to the bell itself. Air flowed through a leather pipe from the lead barrel on the ocean floor to the bell. The diver could breathe the air from a position inside the bell, or he could move around outside the bell wearing a diving suit that consisted of a lead bell-shaped helmet with a glass viewing window and a leather body suit, with a leather pipe carrying fresh air from the diving bell to the helmet.

The subject of the preceding passage was most likely Halley’s _____.

A. childhood

B. work as an astronomer

C. invention of the diving bell

D. many different interests

1

NH

Nguyen Hoang Hai

22 tháng 2 2019

Đáp án B

Chủ đề của đoạn văn phía trước đoạn này có thể là về công việc là một nhà thiên văn học của Halley

Để trả lời câu hỏi này, thông tin thường nằm ở 1, 2 câu đầu tiên của đoạn văn – là câu nối giữa đoạn văn trước với đoạn văn này: “Though Edmund Halley was most famous because of his achievements as an astronomer, he was a scientist of diverse interests and great skill” Mặc dù Edmund Halley nổi tiếng nhất vì những thành tựu của ông như một nhà thiên văn học nhưng ông cũng là một nhà khoa học có nhiều sở thích và kỹ năng tuyệt vời.

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 from 38 to 42.(1) Though Edmund Halley was most famous because of his achievements as an astronomer, he was a scientist of diverse interests and great skill. In addition to studying the skies, Halley was also deeply interested in exploring the unknown depths of the oceans. One of his lesser-known accomplishments that were quite remarkable was his design for a...

DM

Dương Minh

12 tháng 3 2018

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 from 38 to 42.

(1) Though Edmund Halley was most famous because of his achievements as an astronomer, he was a scientist of diverse interests and great skill. In addition to studying the skies, Halley was also deeply interested in exploring the unknown depths of the oceans. One of his lesser-known accomplishments that were quite remarkable was his design for a diving bell that facilitated exploration of the watery depths.

(2) The diving bell that Halley designed had a major advantage over the diving bells that were in use prior to his. Earlier diving bells could only make use of the air contained within the bell itself, so divers had to surface when the air inside the bell ran low. Halley’s bell was an improvement in that its design allowed for an additional supply of fresh air that enabled a crew of divers to remain underwater for several hours.

(3) The diving contraption that Halley designed was in the shape of a bell that measured three feet across the top and five feet across the bottom and could hold several divers comfortably; it was open at the bottom so that divers could swim in and out at will. The bell was built of wood, which was first heavily tarred to make it water repellent and was then covered with a half-ton sheet of lead to make the bell heavy enough to sink in water. The bell shape held air inside for the divers to breathe as the bell sank to the bottom.

(4) The air inside the bell was not the only source of air for the divers to breathe, and it was this improvement that made Halley’s bell superior to its predecessors. In addition to the air already in the bell, air was also supplied to the divers from a lead barrel that was lowered to the ocean floor close to the bell itself. Air flowed through a leather pipe from the lead barrel on the ocean floor to the bell. The diver could breathe the air from a position inside the bell, or he could move around outside the bell wearing a diving suit that consisted of a lead bell-shaped helmet with a glass viewing window and a leather body suit, with a leather pipe carrying fresh air from the diving bell to the helmet.

Halley’s bell was better than its predecessors because it _____.

A. was bigger

B. provided more air

C. weighed less

D. could rise more quickly

1

NH

Nguyen Hoang Hai

12 tháng 3 2018

Đáp án B

Đáp án được tìm thấy ở dòng 3 + 4 đoạn (2) Halley’s bell was an improvement in that its design allowed for an additional supply of fresh air that enabled a crew of divers to remain underwater for several hours. Chuông của Halley đã được cải tiến trong thiết kế của nó cho phép cung cấp thêm một lượng không khí cho phép một đoàn thợ lặn ở dưới nước trong vài giờ.

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 from 38 to 42.(1) Though Edmund Halley was most famous because of his achievements as an astronomer, he was a scientist of diverse interests and great skill. In addition to studying the skies, Halley was also deeply interested in exploring the unknown depths of the oceans. One of his lesser-known accomplishments that were quite remarkable was his design for a...

DM

Dương Minh

22 tháng 9 2017

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 from 38 to 42.

(1) Though Edmund Halley was most famous because of his achievements as an astronomer, he was a scientist of diverse interests and great skill. In addition to studying the skies, Halley was also deeply interested in exploring the unknown depths of the oceans. One of his lesser-known accomplishments that were quite remarkable was his design for a diving bell that facilitated exploration of the watery depths.

(2) The diving bell that Halley designed had a major advantage over the diving bells that were in use prior to his. Earlier diving bells could only make use of the air contained within the bell itself, so divers had to surface when the air inside the bell ran low. Halley’s bell was an improvement in that its design allowed for an additional supply of fresh air that enabled a crew of divers to remain underwater for several hours.

(3) The diving contraption that Halley designed was in the shape of a bell that measured three feet across the top and five feet across the bottom and could hold several divers comfortably; it was open at the bottom so that divers could swim in and out at will. The bell was built of wood, which was first heavily tarred to make it water repellent and was then covered with a half-ton sheet of lead to make the bell heavy enough to sink in water. The bell shape held air inside for the divers to breathe as the bell sank to the bottom.

(4) The air inside the bell was not the only source of air for the divers to breathe, and it was this improvement that made Halley’s bell superior to its predecessors. In addition to the air already in the bell, air was also supplied to the divers from a lead barrel that was lowered to the ocean floor close to the bell itself. Air flowed through a leather pipe from the lead barrel on the ocean floor to the bell. The diver could breathe the air from a position inside the bell, or he could move around outside the bell wearing a diving suit that consisted of a lead bell-shaped helmet with a glass viewing window and a leather body suit, with a leather pipe carrying fresh air from the diving bell to the helmet.

It is NOT stated in the passage that Halley’s bell _____.

A. was completely enclosed

B. was wider at the top than at the bottom

C. could hold more than one diver

D. was made of tarred wood

1

NH

Nguyen Hoang Hai

22 tháng 9 2017

Đáp án A

Người ta không nói trong đoạn văn rằng chuông của Halley…

A: Được bao quanh hoàn toàn

B: Ở dưới rộng hơn ở trên. Thông tin này tìm thấy ở dòng 1 +2 đoạn 3: The diving contraption that Halley designed was in the shape of a bell that measured three feet across the top and five feet across the bottom Thiết bị lặn mà Halley thiết kế có hình dạng của một cái chuông rộng 3 feet ở phía đầu chuông và rộng 5 feet ở đáy chuông

C: Có thể chứa hơn 1 thợ lặn Thông tin này tìm thấy ở dòng 1 +2 đoạn 3: The diving contraption that Halley designed was in the shape of a bell that measured three feet across the top and five feet across the bottom and could hold several divers comfortably. Thiết bị lặn mà Halley thiết kế có hình dạng của một cái chuông rộng 3 feet ở phía đầu chuông và rộng 5 feet ở đáy chuông và có thể thoải mái chứa nhiều thợ lặn

D: Được làm bằng gỗ phủ hắc ín. Thông tin được tìm thấy ở dòng 3 đoạn 3: “The bell was built of wood, which was first heavily tarred” Chuông được làm bằng gỗ, lần đầu được phủ lớp hắc ín dầy

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 from 38 to 42.(1) Though Edmund Halley was most famous because of his achievements as an astronomer, he was a scientist of diverse interests and great skill. In addition to studying the skies, Halley was also deeply interested in exploring the unknown depths of the oceans. One of his lesser-known accomplishments that were quite remarkable was his design for a...

DM

Dương Minh

7 tháng 12 2019

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 from 38 to 42.

(1) Though Edmund Halley was most famous because of his achievements as an astronomer, he was a scientist of diverse interests and great skill. In addition to studying the skies, Halley was also deeply interested in exploring the unknown depths of the oceans. One of his lesser-known accomplishments that were quite remarkable was his design for a diving bell that facilitated exploration of the watery depths.

(2) The diving bell that Halley designed had a major advantage over the diving bells that were in use prior to his. Earlier diving bells could only make use of the air contained within the bell itself, so divers had to surface when the air inside the bell ran low. Halley’s bell was an improvement in that its design allowed for an additional supply of fresh air that enabled a crew of divers to remain underwater for several hours.

(3) The diving contraption that Halley designed was in the shape of a bell that measured three feet across the top and five feet across the bottom and could hold several divers comfortably; it was open at the bottom so that divers could swim in and out at will. The bell was built of wood, which was first heavily tarred to make it water repellent and was then covered with a half-ton sheet of lead to make the bell heavy enough to sink in water. The bell shape held air inside for the divers to breathe as the bell sank to the bottom.

(4) The air inside the bell was not the only source of air for the divers to breathe, and it was this improvement that made Halley’s bell superior to its predecessors. In addition to the air already in the bell, air was also supplied to the divers from a lead barrel that was lowered to the ocean floor close to the bell itself. Air flowed through a leather pipe from the lead barrel on the ocean floor to the bell. The diver could breathe the air from a position inside the bell, or he could move around outside the bell wearing a diving suit that consisted of a lead bell-shaped helmet with a glass viewing window and a leather body suit, with a leather pipe carrying fresh air from the diving bell to the helmet.

The expression “at will” in paragraph 3 could best be replaced by

A. in the future

B. upside down

C. as they wanted

D. with great speed

1

NH

Nguyen Hoang Hai

7 tháng 12 2019

Đáp án C

- at will: tùy theo ý muốn, tùy ý = as they wanted: như họ muốn

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 from 36 to 42.WATER SPORTSRecreational diving or sport diving is a type of diving that uses scuba equipment for the purpose of leisure and enjoyment. In some diving circles, the term "recreational diving" is used in contradistinction to "technical diving", a more demanding aspect of the sport which requires greater levels of training, experience and...

DM

Dương Minh

14 tháng 4 2017

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 from 36 to 42.

WATER SPORTS

Recreational diving or sport diving is a type of diving that uses scuba equipment for the purpose of leisure and enjoyment. In some diving circles, the term "recreational diving" is used in contradistinction to "technical diving", a more demanding aspect of the sport which requires greater levels of training, experience and equipment.

Recreational scuba diving grew out of related activities such as snorkeling and underwater hunting. For a long time, recreational underwater excursions were limited by the amount of breath that could be held. However, the invention of the aqualung in 1943 by Jacques-Yves Cousteau and its development over subsequent years led to a revolution in recreational diving. However, for much of the 1950s and early1960s, recreational scuba diving was a sport limited to those who were able to afford or make their own kit, and prepared to undergo intensive training to use it. As the sport became more popular, manufacturers became aware of the potential market, and equipment began to appear that was easy to use, affordable and reliable. Continued advances in' SCUBA technology, such as buoyancy compensators, modern diving regulators, wet or dry suits, and dive computers, increased the safety, comfort and convenience of the gear encouraging more people to train and use it.

Until the early 1950s, navies and other organizations performing professional diving were the only providers of diver training, but only for their own personnel and only using their own types of equipment. There were no training courses available to civilians who bought the first scuba equipment. Professional instruction started in 1959 when the non-profit National Association of Underwater Instructors was formed.

Further developments in technology have reduced the cost of training and diving. Scuba-diving has become a popular leisure activity, and many diving locations have some form of dive shop presence that can offer air fills, equipment and training. In tropical and sub-tropical parts of the world, there is a large market in holiday divers, who train and dive while on holiday, but rarely dive close to home. Generally, recreational diving depths are limited to a maximum of between 30 and 40 meters (100 and 130 feet), beyond which a variety of safety issues make it unsafe to dive using recreation diving equipment and practices, and specialized training and equipment for technical diving are needed.

According to the second paragraph, in the 1950s and early 1960s, recreational scuba diving was a sport limited because _______.

A. divers did not like to take part in any intensive training courses

B. there were not any intensive training courses for divers

C. there were not enough kit for many divers

D. kit and intensive training were too expensive for many people to afford

1

NH

Nguyen Hoang Hai

14 tháng 4 2017

Đáp án D

Theo như đoạn văn số 2, trong suốt những năm 1950 và 1960, môn lặn giải trí là một thể thao chỉ dành cho một số người nhất định bởi ________.

A. Những người lặn không thích tham gia vao các khóa huấn luyện chuyên sâu

B. Không có bất cứ một khóa huấn luyện chuyên sâu nào cho người lặn

C. Không có đủ đồ cho nhiều người lặn

D. Đồ lặn và các khóa huấn luyện chuyên sâu là quá đắt cho nhiều người có thể trả.

Theo thông tin của đoạn văn số 2:

However, for much of the 19505 and early19605, recreational scuba diving was a sport limited to those who were able to afford or make their own kit, and prepared to undergo intensive training to use it. (Tuy nhiên, trong những năm 1950 và 1960, môn lặn giải trí là một môn thể thao chỉ dành cho những người người mà có thể đủ sức trả cho những đồ lặn và những khóa huấn luyện chuyên sâu để thực hành nó.)

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 from 36 to 42.WATER SPORTSRecreational diving or sport diving is a type of diving that uses scuba equipment for the purpose of leisure and enjoyment. In some diving circles, the term "recreational diving" is used in contradistinction to "technical diving", a more demanding aspect of the sport which requires greater levels of training, experience and...

DM

Dương Minh

2 tháng 5 2018

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 from 36 to 42.

WATER SPORTS

Recreational diving or sport diving is a type of diving that uses scuba equipment for the purpose of leisure and enjoyment. In some diving circles, the term "recreational diving" is used in contradistinction to "technical diving", a more demanding aspect of the sport which requires greater levels of training, experience and equipment.

Recreational scuba diving grew out of related activities such as snorkeling and underwater hunting. For a long time, recreational underwater excursions were limited by the amount of breath that could be held. However, the invention of the aqualung in 1943 by Jacques-Yves Cousteau and its development over subsequent years led to a revolution in recreational diving. However, for much of the 1950s and early1960s, recreational scuba diving was a sport limited to those who were able to afford or make their own kit, and prepared to undergo intensive training to use it. As the sport became more popular, manufacturers became aware of the potential market, and equipment began to appear that was easy to use, affordable and reliable. Continued advances in' SCUBA technology, such as buoyancy compensators, modern diving regulators, wet or dry suits, and dive computers, increased the safety, comfort and convenience of the gear encouraging more people to train and use it.

Until the early 1950s, navies and other organizations performing professional diving were the only providers of diver training, but only for their own personnel and only using their own types of equipment. There were no training courses available to civilians who bought the first scuba equipment. Professional instruction started in 1959 when the non-profit National Association of Underwater Instructors was formed.

Further developments in technology have reduced the cost of training and diving. Scuba-diving has become a popular leisure activity, and many diving locations have some form of dive shop presence that can offer air fills, equipment and training. In tropical and sub-tropical parts of the world, there is a large market in holiday divers, who train and dive while on holiday, but rarely dive close to home. Generally, recreational diving depths are limited to a maximum of between 30 and 40 meters (100 and 130 feet), beyond which a variety of safety issues make it unsafe to dive using recreation diving equipment and practices, and specialized training and equipment for technical diving are needed.

Holiday divers _________.

A. do not like to dive in tropical and sub-tropical parts

B. can dive as deep as they like because of safety

C. are those who go away from home to dive

D. are limited in tropical and sub-tropical parts

1

NH

Nguyen Hoang Hai

2 tháng 5 2018

Đáp án C

Holiday divers ________.

A. Không thích lặn ở những vùng nhiệt đới và cận nhiệt đới

B. Có thể lặn sâu như họ thích bởi vì có sự an toàn

C. Là những người mà đi xa nhà để lặn

D. Chỉ tập trung ở những vùng nhiệt đới và cận nhiệt đới.

Theo thông tin ở đoạn văn cuối:

In tropical and sub-tropical parts of the world, there is a large market in holiday divers, who train and dive while on holiday, but rarely dive close to home. (Ở những vùng nhiệt đới và cận nhiệt đới có một thị trường cho những holiday divers, là những người tập luyện và lặn trong kì nghỉ nhưng hiếm khi nào lại lặn ở gần nhà.)

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 from 36 to 42.WATER SPORTSRecreational diving or sport diving is a type of diving that uses scuba equipment for the purpose of leisure and enjoyment. In some diving circles, the term "recreational diving" is used in contradistinction to "technical diving", a more demanding aspect of the sport which requires greater levels of training, experience and...

DM

Dương Minh

9 tháng 1 2019

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 from 36 to 42.

WATER SPORTS

Recreational diving or sport diving is a type of diving that uses scuba equipment for the purpose of leisure and enjoyment. In some diving circles, the term "recreational diving" is used in contradistinction to "technical diving", a more demanding aspect of the sport which requires greater levels of training, experience and equipment.

Recreational scuba diving grew out of related activities such as snorkeling and underwater hunting. For a long time, recreational underwater excursions were limited by the amount of breath that could be held. However, the invention of the aqualung in 1943 by Jacques-Yves Cousteau and its development over subsequent years led to a revolution in recreational diving. However, for much of the 1950s and early1960s, recreational scuba diving was a sport limited to those who were able to afford or make their own kit, and prepared to undergo intensive training to use it. As the sport became more popular, manufacturers became aware of the potential market, and equipment began to appear that was easy to use, affordable and reliable. Continued advances in' SCUBA technology, such as buoyancy compensators, modern diving regulators, wet or dry suits, and dive computers, increased the safety, comfort and convenience of the gear encouraging more people to train and use it.

Until the early 1950s, navies and other organizations performing professional diving were the only providers of diver training, but only for their own personnel and only using their own types of equipment. There were no training courses available to civilians who bought the first scuba equipment. Professional instruction started in 1959 when the non-profit National Association of Underwater Instructors was formed.

Further developments in technology have reduced the cost of training and diving. Scuba-diving has become a popular leisure activity, and many diving locations have some form of dive shop presence that can offer air fills, equipment and training. In tropical and sub-tropical parts of the world, there is a large market in holiday divers, who train and dive while on holiday, but rarely dive close to home. Generally, recreational diving depths are limited to a maximum of between 30 and 40 meters (100 and 130 feet), beyond which a variety of safety issues make it unsafe to dive using recreation diving equipment and practices, and specialized training and equipment for technical diving are needed.

Which of the following could best replace the word "subsequent" ?

A. successive

B. following

C. ancient

D. succeeding

1

NH

Nguyen Hoang Hai

9 tháng 1 2019

Đáp án B

Từ “subsequent” có thể thay thế bằng từ nào dưới đây:

A. successive (a): liên tục, liên tiếp B. following (a): theo sau, nối tiếp

C. ancient (a): cổ xưa D. succeeding (a); tiếp theo, thừa kế

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 from 36 to 42.WATER SPORTSRecreational diving or sport diving is a type of diving that uses scuba equipment for the purpose of leisure and enjoyment. In some diving circles, the term "recreational diving" is used in contradistinction to "technical diving", a more demanding aspect of the sport which requires greater levels of training, experience and...

DM

Dương Minh

5 tháng 9 2019

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 from 36 to 42.

WATER SPORTS

Recreational diving or sport diving is a type of diving that uses scuba equipment for the purpose of leisure and enjoyment. In some diving circles, the term "recreational diving" is used in contradistinction to "technical diving", a more demanding aspect of the sport which requires greater levels of training, experience and equipment.

Recreational scuba diving grew out of related activities such as snorkeling and underwater hunting. For a long time, recreational underwater excursions were limited by the amount of breath that could be held. However, the invention of the aqualung in 1943 by Jacques-Yves Cousteau and its development over subsequent years led to a revolution in recreational diving. However, for much of the 1950s and early1960s, recreational scuba diving was a sport limited to those who were able to afford or make their own kit, and prepared to undergo intensive training to use it. As the sport became more popular, manufacturers became aware of the potential market, and equipment began to appear that was easy to use, affordable and reliable. Continued advances in' SCUBA technology, such as buoyancy compensators, modern diving regulators, wet or dry suits, and dive computers, increased the safety, comfort and convenience of the gear encouraging more people to train and use it.

Until the early 1950s, navies and other organizations performing professional diving were the only providers of diver training, but only for their own personnel and only using their own types of equipment. There were no training courses available to civilians who bought the first scuba equipment. Professional instruction started in 1959 when the non-profit National Association of Underwater Instructors was formed.

Further developments in technology have reduced the cost of training and diving. Scuba-diving has become a popular leisure activity, and many diving locations have some form of dive shop presence that can offer air fills, equipment and training. In tropical and sub-tropical parts of the world, there is a large market in holiday divers, who train and dive while on holiday, but rarely dive close to home. Generally, recreational diving depths are limited to a maximum of between 30 and 40 meters (100 and 130 feet), beyond which a variety of safety issues make it unsafe to dive using recreation diving equipment and practices, and specialized training and equipment for technical diving are needed.

What is the topic of the passage?

A. The reasons why people like scuba-diving

B. The history of scuba-diving

C. The equipment for scuba-diving

D. The reasons why not many people take up scuba-diving

1

NH

Nguyen Hoang Hai

5 tháng 9 2019

Đáp án B

Chủ đề WATER SPORTS

Chủ đề của đoạn văn này là gì?

A. Những lí do giải thích tại sao mọi người thích môn lặn

B. Lịch sử của môn lặn

C. Thiết bị cho môn lặn

D. Những lí do giải thích tại sao không có nhiều người luyện tập môn lặn

Xuyên suốt cả bài là nói về lịch sử của môn lặn với rất nhiều sự kiện và mốc thời gian

=> chủ đề của bài là lịch sử của môn lặn.

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 from 36 to 42.WATER SPORTSRecreational diving or sport diving is a type of diving that uses scuba equipment for the purpose of leisure and enjoyment. In some diving circles, the term "recreational diving" is used in contradistinction to "technical diving", a more demanding aspect of the sport which requires greater levels of training, experience and...

DM

Dương Minh

17 tháng 7 2018

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 from 36 to 42.

WATER SPORTS

Recreational diving or sport diving is a type of diving that uses scuba equipment for the purpose of leisure and enjoyment. In some diving circles, the term "recreational diving" is used in contradistinction to "technical diving", a more demanding aspect of the sport which requires greater levels of training, experience and equipment.

Recreational scuba diving grew out of related activities such as snorkeling and underwater hunting. For a long time, recreational underwater excursions were limited by the amount of breath that could be held. However, the invention of the aqualung in 1943 by Jacques-Yves Cousteau and its development over subsequent years led to a revolution in recreational diving. However, for much of the 1950s and early1960s, recreational scuba diving was a sport limited to those who were able to afford or make their own kit, and prepared to undergo intensive training to use it. As the sport became more popular, manufacturers became aware of the potential market, and equipment began to appear that was easy to use, affordable and reliable. Continued advances in' SCUBA technology, such as buoyancy compensators, modern diving regulators, wet or dry suits, and dive computers, increased the safety, comfort and convenience of the gear encouraging more people to train and use it.

Until the early 1950s, navies and other organizations performing professional diving were the only providers of diver training, but only for their own personnel and only using their own types of equipment. There were no training courses available to civilians who bought the first scuba equipment. Professional instruction started in 1959 when the non-profit National Association of Underwater Instructors was formed.

Further developments in technology have reduced the cost of training and diving. Scuba-diving has become a popular leisure activity, and many diving locations have some form of dive shop presence that can offer air fills, equipment and training. In tropical and sub-tropical parts of the world, there is a large market in holiday divers, who train and dive while on holiday, but rarely dive close to home. Generally, recreational diving depths are limited to a maximum of between 30 and 40 meters (100 and 130 feet), beyond which a variety of safety issues make it unsafe to dive using recreation diving equipment and practices, and specialized training and equipment for technical diving are needed.

Recreational underwater excursions used to be limited _______.

A. as underwater hunting was banned

B. because the necessary amount of breath was too expensive to afford

C. because divers could not take enough amount of breath with them

D. because the necessary amount of breath was too heavy to bring

1

NH

Nguyen Hoang Hai

17 tháng 7 2018

Đáp án C

Những chuyến du ngoạn dưới nước trước đây từng bị hạn chế ________.

A. Vì việc săn bắt dưới nước bị cấm

B. Bởi vì những thứ cần thiết đảm bảo cho việc thờ được ở dưới nước là quá đắt để chi trả.

C. Bởi vì những người lặn không thể mang đủ oxi để thở dưới nước

D. Bởi vì những thứ cần thiết cho việc thở ở dưới nước là quá nặng để mang.

Theo thông tin ở đoan văn số 2:

For a long time, recreational underwater excursions were limited by the amount of breath that could be held. (Trong một thời gian dài, những chuyến du ngoạn ở dưới nước đã bị bạn chế bởi số lượng oxi có thế mang theo.)