2017四级考试预测题

【导读】随着时间的进一步推进，距离2020年英语四级考试越来越近了，相信不少小伙伴都在进行紧张的复习备考，特别是英语四级阅读理解是重点中的重点复习对象，为了帮助各位考生更加有针对性的高效的进行复习备考，下面是小编为大家整理的英语四级考题预测之阅读理解题，希望对大家有所帮助。

When blood is sent to the lungs by the heart, it has come back from the cells in the rest of the body. So the blood that goes into the wall of an air sac (Jl) contains much dissolved carbon dioxide but very little oxygen. At the same time, the air that goes into the air sac contains much oxygen but very little carbon dioxide.

You have learned that dissolved materials always diffuse (扩散) from where there is more of them to where there is less. Oxygen from the air dissolves in the moisture on the lining of the air sac and diffuses through the lining into the blood. Meanwhile, carbon dioxide diffuses from the blood into the air sac. The blood then flows from the lungs back to the heart, which sends it out to all other parts of the body.

Soon after air goes into an air sac, it gives up some of its oxygen and takes in some carbon dioxide from the blood. To keep diffusion going as it should, this carbon dioxide must be gotten rid of. Breathing, which is caused by movements of the chest, forces the used air out of the air sacs in your lungs and brings in fresh air. The breathing muscles are controlled automatically so that you breathe at the proper rate to keep your air sacs supplied with fresh air.

Ordinarily, you breathe about twenty-two times a minute. Of course, you breathe faster when you are exercising and slower when you are resting. Fresh air is brought into your lungs when you breathe in, or inhale, while used air is forced out of your lungs when you breathe out, or exhale.

26. In the respiratory process, only one of the following actions takes place: it is_______.

A. the diffusion of blood through capillary walls into air sacs

B. the diffusion of carbon dioxide through capillary and air sac walls into the blood

C. the diffusion of oxygen through the air sac and capillary walls into the blood

D. the exchange of nitrogen within air sacs

27. The number of times per minute that you breathe is_______.

A. independent of your rate of exercise

B. fixed at twenty-two times per minute

C. influenced by your age and sex

D. controlled automatically by an unspecified body mechanism

28. The process by which carbon dioxide and oxygen are transferred does not depend on

A. the presence of nitrogen in the blood

B. breathing muscles

C. the flow of blood

D. the moisture in the air sac linings

29. The author's style in this passage can best be described as---------.

A informal and matter of fact B. impersonal

C. personal P- matter of fact and formal

30. Which of the following words can replace the word "exhale"?

A. Breathe out. B. Breathe in.

C. Diffuse. D. Exchange.

26. C 27. D 28. A 29. A 30. A

以上就是小编今天给大家整理发送的关于“英语四级考题预测之阅读理解题”的相关内容，希望对大家有所帮助。随着社会的发展，英语变得越来越重要，我们应该从小抓起，做好少儿英语启蒙，长大后也不用这么辛苦了，那么如何给孩子做英语启蒙就显得很重要了，科学有效的方法可以取得事半功倍的效果哦!

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2017年12月大学英语四级阅读理解试题及答案（4）

If the population of the earth goes on increasing at its present rate, there will eventually not be enough resources left to sustain life on the planet. By the middle of the 21st century, if present trends continue, we will have used up all the oil that drives our cars, for example. Even if scientists develop new ways of feeding the human race, the crowded conditions on earth will make it necessary for lus to look for open space somewhere else. But none of the other planets in our solar system are capable of supporting life at present. One possible solution to the problem, however, has recently been suggested by American scientist, Professor Carl Sagan.

Sagan believes that before the earth's resources are compleetely exhausted it will be possible to change the atmophere of Venus and so create a new world almost as large as earth itself. The difficult is that Venus is much hotter than the earth and there is only a tiny amount of water there.

Sagan proposes that algae organisms that can live in extremely hot or cold atmospheres and at the same time produce oxygen, should be bred in condition similar to those on Venus. As soon as this has been done, the algae will be placed in small rockets. Spaceship will then fly to Venus and fire the rockets into the atmosphere. In a fairly short time, the alge will break down the carbon dioxide into oxygen and carbon.

When the algae have done theri work, the atmosphere will become cooler, but befor man can set foot on Venus it will be neccessary for the oxygen to produce rain. The surface of the planet will still be too hot for man to land on it but the rain will eventually fall and in a few years something like earth will be reproduced on Venus.

1. Inte long run, the most insoluble problem caused by population growth on earth will probably be the lack of ________.

a. food

b. oil

c. space

d. resources

2. Carl Sagan believes that Venus might be colonized from earth because ________

a. it might be possible to change its atmosphere

b. its atmosphere is the same as the earth's

c. there is a good supply of water on Venus

d. the days on Venus are long enough

3. On Venus there is a lot of ________.

a. water

b. carbon dioxide

c. carbon monoxide

d. oxygen

4. Algae are plants that can ________.

a. live in very hot temperatures

b. live in very cold temperatures

c. manufacture oxygen

d. all of the above

5. Man can land on Venus only when ________.

a. the algae have done their work

b. the atmosphere becomes cooler

c. thereis oxygen

d. it rains there

参考答案：cabdd