For thousands of years, people have looked up at the night sky and looked at the moon. They wondered what the moon was made of.

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问题     For thousands of years, people have looked up at the night sky and looked at the moon. They wondered what the moon was made of. They wanted to know how big it was and how far away it was. One of the most interesting questions was "Where did the moon come from?" No one knew for sure. Scientists developed many different theories, or guesses, but they could not prove that their ideas were correct.
    Then, between 1969 and 1972, the United States sent astronauts to the moon. They studied the moon and returned to the earth with rock samples. Scientists have studied these pieces of rock, the moon’s movements, and information about the moon and the earth. They can finally answer questions about the origin of the moon.
    Today most scientists believe that the moon formed from the earth. They think that a large object hit the earth early in its history. Perhaps the object was as big as Alars. When the object hit the earth, huge pieces of the earth broke off. These pieces then moved around the earth. After a brief time, the pieces came together and formed the moon.
    This "impact (撞击) theory" exposes many facts about the earth and the moon. For example, the moon is very dry because the impact created so much heat that it dried up all the water. The earth has iron in its center. However, the moon has very little iron in its center. This is because the moon formed from lighter materials that make up the outer part of the earth. Finally, the earth and the moon are almost of the same age: the earth is about 4.5 billion years old, while the moon is about 4.4 billion years old.
    No one can prove that something really happened billions of years ago. In the future, new information will either support this theory or show that it is wrong. For now, scientists accept the impact theory because it explains what we know today about the earth and the moon.
Astronauts are people who______.

选项 A、collect rock samples
B、are sent to work in space
C、are interested in the moon
D、study the structure of the moon

答案B

解析 本题为词义猜测题,需根据上下文推断这个单词的含义。根据本段中“They studied the moon and returned to the earth with rock samples.”可以得出结论: “who are sent to work in space”符合“astronauts”的含义,因此选项B为正确答案。选项A.collect rock samples仅仅是astronauts完成的任务之一。选项C则是一个普遍的现象,并非所有感兴趣的人都是astronauts。选项D意为“研究月球的结构”,而astronauts并不是仅仅从事这项活动的人群,因此不是正确答案。
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本试题收录于: 英语题库普高专升本分类
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