2020届一轮复习人教版必修三Unit4Astronomy-the science of star(3)

1．No one knows exactly how the earth began, as it happened so long ago. [句式分析]

[尝试翻译] 没有人确切知道地球是怎样开始的，因为在很久以前它就形成了。

2．What it was to become was uncertain until between 4.5 and 3.8 billion years ago when the dust settled into a solid globe. [句式分析]

[尝试翻译] 随后它变成什么没人确定，直到45～38亿年前，这团尘埃才慢慢地形成了一个固态的球体。

3．What is even more important is that as the earth cooled down, water began to appear on its surface.

[句式分析] 这是一个复合句。what引导主语从句；that引导表语从句；as在表语从句中引导状语从句。

[尝试翻译] 更重要的是，随着地球的不断冷却，地球表面出现了水。 4．So whether life will continue on the earth for millions of years to come will depend on whether this problem can be solved.

[句式分析]

[尝试翻译] 所以，在未来的数百万年中，生命能否在地球上延续取决于这个问题能否得到解决。

Ⅰ.阅读理解 A

Some new comets (彗星) have been discovered accidentally by amateur (业余的) astronomers.Surprisingly a few bright comets have been discovered with the naked eye (肉眼) by members of the general public.However, a great number of comets are found by comet hunters carrying out telescope searches of chosen areas of the night sky.

As the movement of all comets is directed around the Sun and because these bodies brighten as they move towards the Sun, there is a greater possibility for the discovery of a new comet in the skies towards the Sun rather than away from the Sun's direction.This means that searches should be put on the western sky after evening light and on the eastern sky before morning light.

From the astronomical point there is no time during the year which is the best for the discovery of new comets.A search can be done at any time providing there is no bright Moon.

Studies done on the discovery conditions of comets discovered before show that more comets have been discovered in the morning sky than in the evening sky.Thus the smart comet hunter should make sure that morning activity receives as much if not more attention than any evening effort.

In recent times, the use of advanced CCD technology to discover objects close to the Earth will in the future greatly reduce the chances of new comets being found with small telescopes.An example of the new technology is the very successful LINEAR program operating in New Mexico.However, until a similar system is based in the southern half of the Earth there will continue to be chances for the discovery of new comets which come from the south. 语篇解读：本文是说明文。文章介绍了观测彗星的要领。

1．What are comet hunters advised to do? A．Look away from the Sun.

B．Stay where there's bright light.

C．Face the western sky in the daytime. D．Turn to the east in the early morning.

解析：选D 细节理解题。由第二段中的“This means that searches should be put on the western sky after evening light and on the eastern sky before morning light.”可知，早晨太阳出来之前应观测东面的天空。

2．What do we know about the time for the discovery of new comets? A．Days when they're close to the Earth are great chances. B．Certain fixed days are best for watching comets. C．Every day is the same if there's no bright Moon. D．Days with the Moon should never be missed. 解析：选C 细节理解题。由第三段中的“A search can be done at any time providing there is no bright Moon.”可知，只要没有月亮，每一天对彗星猎人来说都一样可以观测。 3．Which of the following is a smart idea for comet hunters? A．Paying more attention in the morning than in the afternoon. B．Being equally serious both in the morning and afternoon. C．Being more relaxed in the morning than in the afternoon. D．Forming a habit of working only in the morning.

解析：选B 推理判断题。由第四段中的“Thus the smart comet hunter should make sure that morning activity receives as much if not more attention than any evening effort.”可知，早晚观测彗星应该投入一样的精力。

4．What can be inferred about the CCD technology? A．It's similar to a telescope. B．It'll disappoint comet hunters. C．It's spreading all over the world. D．It'll make comet hunters feel lucky.

解析：选B 推理判断题。由最后一段中的“the use of advanced CCD technology ...greatly reduce the chances of new comets being found with small telescopes”可知，这种技术降低了追星猎人发现新的彗星的概率，因此他们应该会感到有些失望。 B

Edmund Halley was an English scientist who lived over 200 years ago.He studied the observations of comets which other scientists had made.The orbit of one particular comet was a very difficult mathematical (数学上的) problem.He could not figure it out.Neither could other scientists who dealt with such problems.

However, Halley had a friend named Newton, who was a brilliant mathematician.Newton thought he had already worked out that problem, but he could not find the papers on which he had done it.He told Halley that the orbit of a comet had the shape of an ellipse (椭圆)．

Now Halley set to work.He figured out (解决；计算出) the orbits of some of the comets that had been observed by scientists.He made a surprising discovery.The comets that had appeared in the years 1531, 1607, and 1682 all had the same orbit.Yet their appearances had been 75 to 76 years apart.

This seemed very strange to Halley.The different comets followed the same orbit.The more halley

thought about it, the more he thought that there had not been three different comets, as people thought.He decided that they had simply seen the same comet three times.The comet had gone away and had come back again.

It was an astonishing idea! Halley felt certain enough to make a prediction (预言) of what comet would happen in the future.He decided that this comet would appear in the year 1758.There were 53 years to go before Halley's prediction could be tested.In 1758 the come …… 此处隐藏：5768字，全部文档内容请下载后查看。喜欢就下载吧 ……