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VI. Read the text and classify the following statements. There are eight other planets that travel around the sun. These planets, in order, include Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Earth is located between Venus and Mars. The path the planets use when traveling around the sun is oval-shaped and is called its orbit. Each of the planets in the solar system take a different amount of time to orbit the Sun.Earth takes 365 days or one year to orbit the Sun. The...
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VI. Read the text and classify the following statements.

There are eight other planets that travel around the sun. These planets, in order, include Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Earth is located between Venus and Mars. The path the planets use when traveling around the sun is oval-shaped and is called its orbit. Each of the planets in the solar system take a different amount of time to orbit the Sun.

Earth takes 365 days or one year to orbit the Sun. The other planets take more or less time to orbit the Sun. It takes Mercury 88 days to travel around the Sun, which is the shortest orbit time compared to other planets. The planet taking the longest time to go around the Sun is Neptune. It takes Neptune almost 165 years to travel around the Sun.

Normally, planets located closer to the sun are hotter than planets farther away. Mercury is the planet nearest the sun, and it can have a temperature of 427°C– much hotter than an oven. Venus is not the planet nearest the sun, but it is the hottest, because it has thick clouds. These clouds let the sun’s heat in, but do not let it out. The temperature on Venus can be 460°C.

The four inner planets, Mercury, Venus, Earth, and Mars are made of rock containing many different minerals. The four outer planets, Jupiter, Saturn, Uranus, and Neptune are mostly made up of different gases. Jupiter is made mainly of helium, hydrogen, and water. The four outer planets also have rings that encircle them, with Saturn having the most rings.

Other objects in space include the moons of these six planets. A moon is a celestial object (object in space) that orbits another body in space. There are approximately 173 moons throughout the solar system. Earth has a single moon, Mercury and Venus have none, and the planet with the most moons is Jupiter with 63. Not far behind Jupiter is Saturn with 62 moons.Mars has 2 moons named Phobos and Deimos.

Classify the following statements (1-12) as they relate to the given planets. Write the names of the planet next to the statements.

Mercury

Earth

Jupiter

Uranus

Venus

Mars

Saturn

Neptune

1.    It is the farthest planet from the Sun. ………………..                               

2.    It is the hottest planet. ………………..

3.    It takes the shortest time to orbit the Sun. ………………..

4.    It takes the longest time to go around the Sun. ………………..

5.    The temperature on its surface is about 427°C. ………………..

6.    It has the most rings. ………………..

7.    It has only one moon. ………………..

8.    It has 63 moons. ………………..

9.    It has 62 moons. ………………..

10.  It is located between Venus and Mars. ………………..

11.  It has two moons known as Deimos and Phobos. ………………..

12.  It is made mainly of helium, hydrogen, and water. ………………..

0
Read the dialogue and then decide whether the statements that follow are true or false. Write True or False in your answersheet: A planet is a body in space that revolves around a star. There are nine planets in our solar system, and these nine planets travel around the sun. The names of the planets are Mercury, Venus, Earth, Jupiter, Saturn, Uranus, Neptune, and Pluto. Planets travel in orbits around their stars . All of the planets of the solar system revolve in elliptical orbits. In...
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Read the dialogue and then decide whether the statements that follow are true or false. Write True or False in your answersheet:

A planet is a body in space that revolves around a star. There are nine planets in our solar system, and these nine planets travel around the sun. The names of the planets are Mercury, Venus, Earth, Jupiter, Saturn, Uranus, Neptune, and Pluto. Planets travel in orbits around their stars . All of the planets of the solar system revolve in elliptical orbits. In other words, their orbits are like large, flat circles. The time that it takes a planet to make one revolution around the sun is called its year. The Greek were the first people to recognize and give names to some of the planets. The word planet comes from a Greek word meaning wanderer. If a person wanders, this means that he goes from one place to another and does not have a home. The Greek thought that the planets “wandered” in the sky. However, modern scientists can predict the movement of the planets very accurately

____ 1/ A planet revolves around the Earth.

____2/ Venus, Mars and Neptune are planets and stars.

____ 3/ The Greek were the first to recognize some of the planets.

____ 4/ The planets in our solar system travel around the sun and in elliptical orbits

1
14 tháng 12 2017

__TRUE__ 1/ A planet revolves around the Earth.

__TRUE__2/ Venus, Mars and Neptune are planets and stars.

__TRUE__ 3/ The Greek were the first to recognize some of the planets.

__TRUE__ 4/ The planets in our solar system travel around the sun and in elliptical orbits .

Sao đúng hết vậy ta ( có thể câu 2 là FALSE nhé bạn ) tớ học Anh Văn cũng không tốt lắm đâu . Đúng thì like cho tớ vui vưới nhé !

26 tháng 10 2018

đề bài sai à bạn :v

4 tháng 11 2018

à ừ xin lỗi mình đăng thiếu đề !!

16 tháng 10 2023

1. Mercury
2. Venus
3. Earth
4. Mars
5. Jupiter
6. Saturn
7. Uranus

Put the verbs in brackets in the correct tenses.34. The four planets closest to the sun – Mercury, Venus, Earth, and Mars - (be) ____________called the terrestrial planets because they have solid, rocky surfaces.35. Our grandparents (come)____________ to stay with us next weekend.36. People (wonder)  ____________ for ages whether we are alone in the universe.37. This time next week, we (take)___________ an English test.38. By the end of this year, I (learn) ____________ English for 6 years.39....
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Put the verbs in brackets in the correct tenses.

34. The four planets closest to the sun – Mercury, Venus, Earth, and Mars - (be) ____________called the terrestrial planets because they have solid, rocky surfaces.

35. Our grandparents (come)____________ to stay with us next weekend.

36. People (wonder)  ____________ for ages whether we are alone in the universe.

37. This time next week, we (take)___________ an English test.

38. By the end of this year, I (learn) ____________ English for 6 years.

39. By the end of this century, scientists (discover) ___________ intelligent life.

40. Beagle 2 - the first British spaceship to Mars - (look for)_____________signs of aliens this time next month.

41. Astronauts (travel) _____________ to planets outside our solar system by 2050.

42. I expect your English (improve)      __________ a lot by the time you got back from England.

43. NASA (develop)___________ new aircraft to replace space shuttles by the end of this decade.

2
19 tháng 6 2021

 

34 are

35 are going to come

36 have wondered

37 will be taking

38 will have learned

39, will have discovered

40 is going to look for

41 will be traveling

42 to be improved

43 will be developing

19 tháng 6 2021

1 are

2 are coming

3 have wondered

4 will be taking

5 will have learnt

6 will have discovered

7 will be looking for

8 will have traveled

9 had been improved

10 will have developed

VI.Read the passage carefully, tlien decide whot hen the following,statement are true T) or false (F) There are nine planets in our solar system. These planets each have their atmosphere and environmental conditions. Scientists have been trying to research other planets to see if it is possible for life to exist on the other eight own bodies in space. Mercury and Pluto are probably the most difficult to research because of their position in the solar system. Mercury is so close to the sun...
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VI.Read the passage carefully, tlien decide whot hen the following,statement are true T) or false (F)
There are nine planets in our solar system. These planets each have their atmosphere and environmental conditions. Scientists have been trying to research other planets to see if it is possible for life to exist on the other eight own bodies in space.
Mercury and Pluto are probably the most difficult to research because of their position in the solar system. Mercury is so close to the sun that with our current technology a space shuttle would burn up before it even reached its atmosphere. Pluto is so far away that some scientists believe that it may not even be a planot but a large asteroid or comet. A space shuttle can not trave that far away because it is so far away from the sun that it would freeze.
Many scientists also believe that our solar system is not alone in the uni- with us. It is difficult to know if there is life present elaewhere in the universe. for many years to come. yerse. Many believe there are several other systems that share the uhiverse .The universe is a complex structure of space that may continue to be a mysterey for many years to come
32. There are nine planets in our solar system, besides Earth.
33. It is difficult to study the planet Mercury because it is very close to the sun.
34. We don't know much about Pluto even though we can see it up close
35. Pluto may not be a planet, according to some scientists.
36. Scientists have got enough information about the universe

1
16 tháng 2 2019

VI.Read the passage carefully, tlien decide whot hen the following,statement are true T) or false (F)
There are nine planets in our solar system. These planets each have their atmosphere and environmental conditions. Scientists have been trying to research other planets to see if it is possible for life to exist on the other eight own bodies in space.
Mercury and Pluto are probably the most difficult to research because of their position in the solar system. Mercury is so close to the sun that with our current technology a space shuttle would burn up before it even reached its atmosphere. Pluto is so far away that some scientists believe that it may not even be a planot but a large asteroid or comet. A space shuttle can not trave that far away because it is so far away from the sun that it would freeze.
Many scientists also believe that our solar system is not alone in the uni- with us. It is difficult to know if there is life present elaewhere in the universe. for many years to come. yerse. Many believe there are several other systems that share the uhiverse .The universe is a complex structure of space that may continue to be a mysterey for many years to come
32. There are nine planets in our solar system, besides Earth. T
33. It is difficult to study the planet Mercury because it is very close to the sun.T
34. We don't know much about Pluto even though we can see it up close F
35. Pluto may not be a planet, according to some scientists. T
36. Scientists have got enough information about the universe F

#Yumi

1-10) Choose the word or phrase that best fits the blank space in each sentence: 1/ The story about UFOs caught the ___________ of the whole class . A. decision B. imagination C. evidence D. science 2/ There’s no _____________ that life exists on other planets. A. creature B. experience C. evidence D. condition 3/ The satellite moves around the earth’s _________ round the sun. A. surface B. path C. space D. orbit 4/ My grandfather is keen __________ growing fruit trees. A. of...
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1-10) Choose the word or phrase that best fits the blank space in each sentence:

1/ The story about UFOs caught the ___________ of the whole class .

A. decision B. imagination C. evidence D. science

2/ There’s no _____________ that life exists on other planets.

A. creature B. experience C. evidence D. condition

3/ The satellite moves around the earth’s _________ round the sun.

A. surface B. path C. space D. orbit

4/ My grandfather is keen __________ growing fruit trees.

A. of B. in C. on D. for

5/ Articles and reports in newspapers talk lots about UFO _____________ .

A. shapes B. balloons C. appearance D. exposition

6/ People are talking about the __________ circles on the fields in The Great Britain.

A. secret B. mysterious C. marvelous D. excellent

7/ UFO’s mean ___________ flying objects.

A. unsafe B. unknown C. unable D. unidentified

8/ Some scientists and government want to send ___________ to Mars.

A. pilots B. aliens C. astronauts D. students

9/ What scenes on the earth can you see from __________ space.

A. out B. outer C. upper D. inner

10/ I think UFOs exist only in films for ___________ .

A. imagination B. persuasion C. entertainment D. introduction

Use the correct form of the words in parentheses:

17/ I think UFOs might be the ___________ of people. ( imagine)

18/ There is no __________ that they have been there. ( evident)

19/ There may be a lot of __________ stones in Mars. ( preciosity)

20/ Many reports talked a lot about the __________ of UFOs . ( appear)

21/ It was a really _________ football match. (excite)

22/ You have had to make a difficult _________ . ( decide)

(23-28) Choose the word or phrase that best fits the blank space in the following passage:

On October 21, 1978, Australian pilot Frederick Valentich, age 20, took off from Melbourne and (23)__________ towards a small island. It was the young men’s first solo night over water. It was a still, clear evening, and from his Cessna aircraft Valentich had a perfect (24) _________ of the sky above and the sea below. Shortly after taking off, Valentich reported to flight controllers in Melbourne that he was being followed by a UFO. “ It’s a long shape,” he reported, “ with a green light, sort of metallic like, all shiny on the outside”. A few minutes later, he told the controllers, “ That strange aircraft is hovering on top of me again.” After that Valentich stopped talking. For the next fourteen seconds the traffic controllers heard a strange ringing sound. Then silence. Valentich and his plane never reached the island, and no (25) __________ of him or his aircraft was ever found. Several (26) __________ of the public report seeing strange phenomena in the sky over Melbourne that night. An amateur photographer produced a photo of (27) __________ looked like a large object surrounded by vapor. A NASA scientist, Richard Haines, heard about the story and began an (28) __________. He analyzed Valentich’s voice on tape and the strange sound heard at the end of the tape. But he concluded that it was “ unidentifiable.” He decided that there were four possible explanations for the mystery surroundings Valentich disappearance: (1) Valentich might have become confused and disoriented while flying his plane and finally crashed; (2) He could have staged a deliberate hoax;(3) he could have been the victim of a top secret advanced weapons test; or he may have benn captured by the occupants of a OFO.

23/ A. headed B. pointed C. directed D. guided

24/ A. sight B. look C. view D. spectacle

25/ A. mark B. trace C. trail D. lead

26/ A. members B. beings C. sessions D. units

27/ A. that B. which C. such D. what

28/ A. identification B. investigation C. interrogation D. introspection

(29-32) Read the dialogue and then decide whether the statements that follow are true or false. Write True or False in your answersheet:

A planet is a body in space that revolves around a star. There are nine planets in our solar system, and these nine planets travel around the sun. The names of the planets are Mercury, Venus, Earth, Jupiter, Saturn, Uranus, Neptune, and Pluto. Planets travel in orbits around their stars . All of the planets of the solar system revolve in elliptical orbits. In other words, their orbits are like large, flat circles. The time that it takes a planet to make one revolution around the sun is called its year. The Greek were the first people to recognize and give names to some of the planets. The word planet comes from a Greek word meaning wanderer. If a person wanders, this means that he goes from one place to another and does not have a home. The Greek thought that the planets “wandered” in the sky. However, modern scientists can predict the movement of the planets very accurately

____ 29/ A planet revolves around the Earth.

____30/ Venus, Mars and Neptune are planets and stars.

____ 31/ The Greek were the first to recognize some of the planets.

____ 32/ The planets in our solar system travel around the sun and in elliptical orbits

(33-36) Rewrite the sentences so that they are nearest in meaning to the sentence

printed before them.

33/ My cousin will meet you at the station.

 You __________________________________________________

34/ It’s possible to travel to Russia without a visa.

You can’t travel to Russia if____________­­­­­­­­­______________________________

35/ The police said : “ Don’t touch anything in this room, everybody. ”

 ____________________________________________________

36/ You don’t do any exercise and that’s why you put on weight.

If _____________________________________________________

4
14 tháng 12 2017

1-10) Choose the word or phrase that best fits the blank space in each sentence:

1/ The story about UFOs caught the ___________ of the whole class .

A. decision B. imagination C. evidence D. science

2/ There’s no _____________ that life exists on other planets.

A. creature B. experience C. evidence D. condition

3/ The satellite moves around the earth’s _________ round the sun.

A. surface B. path C. space D. orbit

4/ My grandfather is keen __________ growing fruit trees.

A. of B. in C. on D. for

5/ Articles and reports in newspapers talk lots about UFO _____________ .

A. shapes B. balloons C. appearance D. exposition

6/ People are talking about the __________ circles on the fields in The Great Britain.

A. secret B. mysterious C. marvelous D. excellent

7/ UFO’s mean ___________ flying objects.

A. unsafe B. unknown C. unable D. unidentified

8/ Some scientists and government want to send ___________ to Mars.

A. pilots B. aliens C. astronauts D. students

9/ What scenes on the earth can you see from __________ space.

A. out B. outer C. upper D. inner

10/ I think UFOs exist only in films for ___________ .

A. imagination B. persuasion C. entertainment D. introduction

14 tháng 12 2017

(23-28) Choose the word or phrase that best fits the blank space in the following passage:

On October 21, 1978, Australian pilot Frederick Valentich, age 20, took off from Melbourne and (23)__________ towards a small island. It was the young men’s first solo night over water. It was a still, clear evening, and from his Cessna aircraft Valentich had a perfect (24) _________ of the sky above and the sea below. Shortly after taking off, Valentich reported to flight controllers in Melbourne that he was being followed by a UFO. “ It’s a long shape,” he reported, “ with a green light, sort of metallic like, all shiny on the outside”. A few minutes later, he told the controllers, “ That strange aircraft is hovering on top of me again.” After that Valentich stopped talking. For the next fourteen seconds the traffic controllers heard a strange ringing sound. Then silence. Valentich and his plane never reached the island, and no (25) __________ of him or his aircraft was ever found. Several (26) __________ of the public report seeing strange phenomena in the sky over Melbourne that night. An amateur photographer produced a photo of (27) __________ looked like a large object surrounded by vapor. A NASA scientist, Richard Haines, heard about the story and began an (28) __________. He analyzed Valentich’s voice on tape and the strange sound heard at the end of the tape. But he concluded that it was “ unidentifiable.” He decided that there were four possible explanations for the mystery surroundings Valentich disappearance: (1) Valentich might have become confused and disoriented while flying his plane and finally crashed; (2) He could have staged a deliberate hoax;(3) he could have been the victim of a top secret advanced weapons test; or he may have benn captured by the occupants of a OFO.

23/ A. headed B. pointed C. directed D. guided

24/ A. sight B. look C. view D. spectacle

25/ A. mark B. trace C. trail D. lead

26/ A. members B. beings C. sessions D. units

27/ A. that B. which C. such D. what

28/ A. identification B. investigation C. interrogation D. introspection

Read the passage and mark A, B, C or D to indicate the correct answer to each of the questions. Jupiter is the largest and most massive planet and is fifth in order of distance from the sun. It is well placed for observation for several months in every year and on average is the brightest of the planets apart from Venus, though for relatively brief periods Mars may outshine it. Jupiter’s less than 10 hour rotation period gives it the shortest day in the solar system in so far as the principal...
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Read the passage and mark A, B, C or D to indicate the correct answer to each of the questions.

 Jupiter is the largest and most massive planet and is fifth in order of distance from the sun. It is well placed for observation for several months in every year and on average is the brightest of the planets apart from Venus, though for relatively brief periods Mars may outshine it. Jupiter’s less than 10 hour rotation period gives it the shortest day in the solar system in so far as the principal planets are concerned. There are no true seasons on Jupiter because the axial inclination to the perpendicular of the orbital plane is only just over 3°-less than that for any other planet.

 The most famous mark on Jupiter is the Great Red Spot. It has shown variations in both intensity and color, and at times it has been invisible, but it always returns after a few years. At its greatest extent it may be 40,000 kilometers long and 14,000 kilometers wide, so its surface area is greater than that of Earth. Though the latitude of the Red Spot varies little, it drifts about in longitude. Over the past century the total longitudinal drift has amounted to approximately 1200°. The latitude is generally very close to -22°. It was once thought that the Red Spot might be a solid or semisolid body floating in Jupiter’s outer gas. However, the Pioneer and Voyager results have refuted that idea and proven the Red Spot to be a phenomenon of Jovian meteorology. Its longevity may well due to its exceptional size, but there are signs that it is decreasing in size, and it may not be permanent. Several smaller red spots have been seen occasionally but have not lasted.
Question:
According to the passge, which of the following is NOT true?

A. Jupiter is bigger than all the other planest in the solar system.

B. A day in Jupiter is nearly 10 hours long.

C. The Red Great Spot moves more vertically than horizontally.

D. Scientists have proof showing that smaller red spots are increasing their size to become other Great Red Spots.

1
11 tháng 3 2017

Đáp án D

Kiến thức: Đọc hiểu

Giải thích:

Theođoạn văn, điều sau đây KHÔNG đúng?

A. Mộc tinh lớn hơn tất cả các hành tinh khác trong hệ mặt trời.

B. Một ngày ở sao Mộc kéo dài gần 10 giờ.

C. Điểm Đỏ di chuyển nhiều theo chiều dọc hơn chiều ngang.

D. Các nhà khoa học có bằng chứng cho thấy các đốm đỏ nhỏ hơn đang gia tăng kích thước của chúng để trở thành các Điểm Đỏ khác.

Dẫn chứng: Several smaller red spots have been seen occasionally but have not lasted.

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 35 to 42. Life in the Universe    Exobiology is the study of life that originates from outside of Earth. As yet, of course, no such a life forms have been found. Exobiologists, however, have done important work in the theoretical study of where life is most likely to evolve, and what those extraterrestrial life forms might be like.What sorts of planets...
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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 from 35 to 42.

 

Life in the Universe

    Exobiology is the study of life that originates from outside of Earth. As yet, of course, no such a life forms have been found. Exobiologists, however, have done important work in the theoretical study of where life is most likely to evolve, and what those extraterrestrial life forms might be like.

What sorts of planets are most likely to develop life? Most scientists likely to agree that a habitable planet must be terrestrial, or rock-based, with liquid surface water and biogeochemical cycles that somewhat resemble the continuous movement ands transformation of materials in the environment. These cycles include the circulation of elements and nutrients upon which life and the Earth’climate depend. Since (as far as we know) all life is carbon-based, a stable carbon cycle is especially important.

The habitable zone is the region around a star in which planets can develop life. Assuming the need for liquid surface water, it follows that most stars around the size of our sun will be able to sustain habitable zones for billions of years. Stars that are larger than the sun are much hotter and burn out more quickly; life there may not have enough time to evolve. Stars that are smaller than the sun have different problems. First of all, planets is their habitable zones will be so close to the stars that they will be “tidally blocked”- that is one side of the planet will always face the star in perpetual daylight with the other side in perpetual night. Another possible obstacle to life on smaller stars is that they tend to vary in their luminosity, or brightness, due to flares and “star spots”. The variation can be large enough to have harmful effects on the ecosystem. 
Of course, not all stars of the right size will give rise to life; they also must have terrestrial planets with the right kind of orbits. Most solar systems have more than one planet, which influence each other’s orbits with their own gravity. Therefore, in order to have a stable system with no planets flying out into space, the width of a star’s habitable zone. This means that for life to evolve, the largest possible number of life-supporting planets in any star’s habitable zone is two. 
Finally, not all planets meeting the above conditions will necessarily develop life. One major threat is large, frequent asteroid and comet impacts, which will wipe out life each time it tries to evolve. The case of Earth teaches that having large gas gains, such as Saturn and Jupiter, in the outer part of the solar system can help keep a planet safe for life. Due to their strong gravitation, they tend to catch or deflect large objects before they can reach Earth

It can be inferred from the paragraph 3 that ______.

A. the Earth is in the sun’s habitable zone

B. the Earth is tidally locked to the sun.

C. the sun varies in its luminosity.

D. variations in luminosity help life to develop

1
2 tháng 7 2019

Đáp án A

Có thể được suy ra từ đoạn 3 rằng ______.

A. Trái đất nằm trong vùng có thể sinh sống của mặt trời.

B. Trái đất bị khóa chặt với mặt trời.

C. Mặt trời thay đổi theo độ sáng.

D. Sự biến đổi trong độ sáng giúp sự sống phát triển.

Được suy ra từ 2 câu đầu- đoạn 3: “The habitable zone is the region around a star in which planets can develop life. Assuming the need for liquid surface water, it follows that most stars around the size of our sun will be able to sustain habitable zones for billions of years” – (Vùng có sự sống là khu vực xung quanh một ngôi sao nơi mà các hành tinh có thể phát triển sự sống. Đảm đương nhu cầu về chất lỏng chảy trên bề mặt, nó cho phép rằng hầu hết những ngôi sao có kích cỡ tương đương với mặt trời của chúng ta có thể duy trì vùng có sự sống qua hành tỉ năm) => Trái đất có sự sống là do nó nằm trong “habitable zones” của Mặt trời, mà “habitable zones” đó được Mặt trời duy trì qua hàng tỉ năm

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 35 to 42. Life in the Universe    Exobiology is the study of life that originates from outside of Earth. As yet, of course, no such a life forms have been found. Exobiologists, however, have done important work in the theoretical study of where life is most likely to evolve, and what those extraterrestrial life forms might be like.What sorts of planets...
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 from 35 to 42.

 

Life in the Universe

    Exobiology is the study of life that originates from outside of Earth. As yet, of course, no such a life forms have been found. Exobiologists, however, have done important work in the theoretical study of where life is most likely to evolve, and what those extraterrestrial life forms might be like.

What sorts of planets are most likely to develop life? Most scientists likely to agree that a habitable planet must be terrestrial, or rock-based, with liquid surface water and biogeochemical cycles that somewhat resemble the continuous movement ands transformation of materials in the environment. These cycles include the circulation of elements and nutrients upon which life and the Earth’climate depend. Since (as far as we know) all life is carbon-based, a stable carbon cycle is especially important.

The habitable zone is the region around a star in which planets can develop life. Assuming the need for liquid surface water, it follows that most stars around the size of our sun will be able to sustain habitable zones for billions of years. Stars that are larger than the sun are much hotter and burn out more quickly; life there may not have enough time to evolve. Stars that are smaller than the sun have different problems. First of all, planets is their habitable zones will be so close to the stars that they will be “tidally blocked”- that is one side of the planet will always face the star in perpetual daylight with the other side in perpetual night. Another possible obstacle to life on smaller stars is that they tend to vary in their luminosity, or brightness, due to flares and “star spots”. The variation can be large enough to have harmful effects on the ecosystem. 
Of course, not all stars of the right size will give rise to life; they also must have terrestrial planets with the right kind of orbits. Most solar systems have more than one planet, which influence each other’s orbits with their own gravity. Therefore, in order to have a stable system with no planets flying out into space, the width of a star’s habitable zone. This means that for life to evolve, the largest possible number of life-supporting planets in any star’s habitable zone is two. 
Finally, not all planets meeting the above conditions will necessarily develop life. One major threat is large, frequent asteroid and comet impacts, which will wipe out life each time it tries to evolve. The case of Earth teaches that having large gas gains, such as Saturn and Jupiter, in the outer part of the solar system can help keep a planet safe for life. Due to their strong gravitation, they tend to catch or deflect large objects before they can reach Earth

The word “which” in paragraph 3 refers to ______.

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11 tháng 1 2018

Đáp án C

Từ “which” ở đoạn 3 ám chỉ tới ______.

A. ngôi sao.

B. vùng.

C. khu vực

D. hành tinh.

Đọc cả câu: “The habitable zone is the region around a star in which planets can develop life” – (Vùng có sự sống là khu vực xung quanh một ngôi sao nơi mà những hành tinh có thể phát triển sự sống).

Như vậy “which” chỉ có thể là thay thế cho “region”.