Once out of the earth’s gravity, the astronau...

Once out of the earth’s gravity, the astronaut is________ by the problem of weightlessness.

高二英语单项填空中等难度题查看答案及解析

The vast majority of us spend our entire lives pulled down by gravity. Then there are astronauts.

This small population of space travelers has given researchers a rare look at what happens to the human body when it’s able to spend large amounts of time outside the downward pull of the Earth. This week, a study on one of the largest groups of astronauts yet ---34 participants---was published in The New England Journal of Medicine.

In the new study, a team of international radiologists supported by NASA looked at MRIs of the brains of astronauts before and after their trips to space. The scientists found that upon returning to Earth, many of the astronauts’ brains had become repositioned inside their skulls, floating higher than before. In addition, the space between certain brain areas appeared to have shrunk. The changes were more common in astronauts who took longer trips into space.

The team characterized astronaut trips as short (an average of less than 14 days) or long (an average of about 165 days). Radiologists who didn't know each astronaut's duration（持续时间）in space compared MRIs from before and after their trips.

Of the 34 total astronauts involved in the study, 18 took long trips to space—spending most of that time on the International Space Station —and of those, 17 returned to Earth with smaller areas between the frontal lobe（脑前额叶）and parietal lobe（顶叶）. The same area of the brain also shrank for three of the 16 astronauts who took shorter trips with the US Space Shuttle Program. The researchers also found that 12 of the ISS astronauts and six of the space-shuttle astronauts returned home with their brains sitting slightly higher in their skulls than before.

It’s not clear what, if anything, these brain changes mean for the health of space travelers. In general, it appears the human body tolerates space travel fairly well: the time astronauts have spent in zero-gravity environments so far doesn’t seem to have had any strong or long-lasting effects.

1.What is the finding of the study?

A. Astronauts have great brain power.

B. Astronauts’ duration in space is updated.

C. Astronauts’ skulls expand after space trips.

D. Astronauts return to Earth with raised brains.

2.How did the scientists draw the conclusion?

A. By analyzing astronauts’ symptoms.

B. By comparing each astronaut’s MRIs.

C. By monitoring astronauts’ brain activities.

D. By observing countless astronauts’ behaviors.

3.What does the author say about the changes inside astronauts’ skulls?

A. They are totally harmless.

B. Their effects are hard to assess.

C. Their occurrence is unavoidable.

D. They will heavily influence astronauts.

4.What is the best title for the text?

A. Effects of zero gravity

B. Valuable experiences of space travel

C. Space travel changes astronauts’ brains

D. Flying long house increases health risks

高二英语阅读理解中等难度题查看答案及解析

The space station spins slowly in ________ space to imitate ________ pull of the earth’s gravity.

高二英语单项填空简单题查看答案及解析

（题文）The tiger, once a ____ animal to humans, is now ____ of disappearing on the earth.

A. dangerous, danger　　 B. dangerous, in danger

C. in danger, in danger　　 D. danger, in danger

高二英语单项填空困难题查看答案及解析

Melissa is fascinated by the variety of our earth’s landscape and her admiration and curiosity are _____ in her new book.

A. refreshed            B. witnessed

C. reflected            D. adjusted

高二英语单项填空中等难度题查看答案及解析

___ most of the earth’s surface is covered by water, fresh water is very rare and precious.

A．As               B．Although          C．If                D．Once

高二英语单项填空中等难度题查看答案及解析

阅读下面的短文，然后按照要求写一篇150词左右的英语短文。

【阅读材料】

A Thirsty World

Three-fourths of the earth’s surface is covered by water, some of which is frozen and most of which is salty. In fact, less than one percent left for all the living things.

Now fresh water is becoming scare, but more and more is needed because of the increasing number of people. Some industries also use amounts of fresh water in the production of things such as steel, paper, and rubber. These factories have polluted water flow into rivers without making it clean. What’s more, people in the city have much dirtied water piped into ditches after cooking every day.

Scientists estimate that the need for fresh water will have doubled by the year 2003. This means that we must find new ways of saving it or producing it. Some nations have worked on the problem and are already sharing their information with others. They are trying to keep their rivers from being polluted. Deep wells are also being dug, and rainwater is being collected in huge artificial lakes. In one way or another, they hope to provide enough water to satisfy the needs of their people. For example, one important way of producing water is to distill(用蒸馏法提取) it from sea water. After the salt has been removed, sea water can be used not only for drinking but also for industry and irrigation. However, the equipment for distillation process is very expensive. Distilled water might be as dear as gold if pollution goes on.

1.   概括短文的内容要点，该部分的字数大约30；

2.   就”环境污染的原因与控制”这个主题发表你的看法，至少包括以下的内容要点，该部分的字数大约120；

a)   环境污染是由什么原因引起的？简单地举例子说明。

b)   为了解决污染问题，国家政府部门应该做些什么？

c)   为了解决污染问题，公民做些什么？

d)   为了解决污染问题，我们学生应该做些什么？

【写作要求】

可以利用实例或其他论述方法支持你的论点，也可以参照阅读材料的内容，但不得直接引用阅读材料中的句子。

高二英语读写任务中等难度题查看答案及解析

阅读下面的短文，然后按照要求写一篇150词左右的英语短文。

【阅读材料】

A Thirsty World

Three-fourths of the earth’s surface is covered by water, some of which is frozen and most of which is salty. In fact, less than one percent left for all the living things.

Now fresh water is becoming scare, but more and more is needed because of the increasing number of people. Some industries also use amounts of fresh water in the production of things such as steel, paper, and rubber. These factories have polluted water flow into rivers without making it clean. What’s more, people in the city have much dirtied water piped into ditches after cooking every day.

Scientists estimate that the need for fresh water will have doubled by the year 2003. This means that we must find new ways of saving it or producing it. Some nations have worked on the problem and are already sharing their information with others. They are trying to keep their rivers from being polluted. Deep wells are also being dug, and rainwater is being collected in huge artificial lakes. In one way or another, they hope to provide enough water to satisfy the needs of their people. For example, one important wayof producing water is to distill(用蒸馏法提取) it from sea water. After the salt has been removed, sea water can be used not only for drinking but also for industry and irrigation. However, the equipment for distillation process is very expensive. Distilled water might be as dear as gold if pollution goes on.

[写作内容]

1.      概括短文的内容要点，该部分的字数大约30；

2.      就”环境污染的原因与控制”这个主题发表你的看法，至少包括以下的内容要点，该部分的字数大约120；

a)      环境污染是由什么原因引起的？简单地举例子说明。

b)     为了解决污染问题，国家政府部门应该做些什么？

c)      为了解决污染问题，公民做些什么？

d)     为了解决污染问题，我们学生应该做些什么？

【写作要求】

可以利用实例或其他论述方法支持你的论点，也可以参照阅读材料的内容，但不得直接引用阅读材料中的句子。

高二英语书面表达简单题查看答案及解析

Earth is believed ______ by an object the size of Mars at some point in the distant past before its

surface cooled.

A. to be hit    　　 　 　 B. to have hit    　　

C. to have been hit    　　 D. to hit

高二英语单项填空中等难度题查看答案及解析

The threats to the health of astronauts in space are very different from ______ on earth.

A. ones             B. that             C. it                   D. those

高二英语单项填空中等难度题查看答案及解析