Question

    Mercury(水星) is the closest planet to the sun. It is a planet slightly larger than the Earth’s moon. It is covered in craters. Some craters have ice in them, even though the planet is hot. Sunlight never touches some parts because of the planet’s special position. Without air, there are great temperature differences between the coldest and hottest parts. Mercury days are so long that there are big differences between temperatures on the daylight side and the night side.

Mercury was created billions of years ago, when big rocks ran into each other. After these accidents, the planet was frequently visited by meteorites (流星) for several hundred million years. There were also many volcanic eruptions. As the planet cooled, the thin, rocky outside shell reduced in diameter(直径) by about 3 kilometers.

The Caloris Basin is one of the largest craters on Mercury. This big crater is 1, 300 kilometers wide and was formed when a large rock, about 100 kilometers across, knocked into the surface. Beethoven, another large crater, is 643 kilometers across.

The cliffs on Mercury are up to 2 kilometers high and hundreds of kilometers long. The cliffs were formed when the thin surface fell apart, as volcanic activity slowed down and Mercury became cooler.

One Mercury day lasts about 59 Earth days. Mercury takes about 88 Earth days to have a complete year, instead of the 365 days that we have on the Earth. Mercury speeds around the sun so that there are three Mercury days every two Mercury years! Mercury has a strange relationship with the Earth. Every 117 days, when Mercury is closest to the Earth, it always has the same side facing us.

Mariner 10 is the only spacecraft to visit Mercury. It made three visits to Mercury in, the 1970s, taking photos of many cliffs and craters. Although the first three visits answered many questions, they have raised others.

1.What is the surface of Mercury like?

A.It’s generally flat. B.It’s hot everywhere.

C.It’s bright everywhere. D.It’s cold in some parts.

2.Why did Mercury’s diameter get smaller?

A.A drop in temperature changed its size.

B.A great many meteorites ran into it.

C.It got out of shape as time passed.

D.Lots of surface rocks fell off.

3.What do we know about Mercury?

A.One Mercury day lasts about 88 Earth days.

B.It turns around the sun faster than the Earth.

C.Six Mercury days are two Mercury years.

D.It has more cliffs than large craters.

4.What happened after Mariner 10’s three visits to Mercury?

A.Another spacecraft visited Mercury.

B.New cliffs and craters were formed.

C.New signs of volcanic activity appeared.

D.Lots of new puzzles needed to be solved.

Answer

1.D

2.A

3.B

4.D

【解析】

这是一篇说明文。文章主要介绍了水星的相关信息以及人类对于水星的探索。

1.细节理解题。根据文章第一段内容“It is covered in craters. Some craters have ice in them, even though the planet is hot.( 它被陨石坑覆盖着。有些陨石坑里有冰，尽管地球很热。)”以及“Without air, there are great temperature differences between the coldest and hottest parts.( 没有空气，最冷和最热的部分之间有很大的温差。)”可知，水星有些陨石坑里有冰，这些部分应该比较寒冷，最冷和最热部分同时并存。故选D项。

2.细节理解题。根据文章第二段末尾内容“As the planet cooled, the thin, rocky outside shell reduced in diameter by about 3 kilometers.( 当行星冷却时，外壳外的薄岩石直径缩小了约3公里。)”可知，直径缩小是由于该行星的温度下降导致。故选A项。

3.推理判断题。根据文章第段内容“Mercury takes about 88 Earth days to have a complete year, instead of the 365 days that we have on the Earth.( 水星大约需要88个地球日才有一个完整的一年，而不是我们在地球上的365天。)”可知，水星的一年为88天，即围绕太阳公转一周的时间为88天，因此可以推知，水星的公转速度比地球快。故选B项。

4.细节理解题。根据文章末尾句内容“Although the first three visits answered many questions, they have raised others.( 虽然前三次访问回答了许多问题，但也提出了其他问题。)”可知，三次访问回答了问题但也带来了新的问题。故选D项。