问题 选择题

下列物质属于纯净物的是(  )

A.淡蓝色的液态氧

B.清澈的泉水

C.清新的空气

D.坚硬的大理石

答案

A、淡蓝色的液态氧中只含有液态氧一种物质,属于纯净物,故选项正确.

B、清澈的泉水中含有水、可溶性的矿物质等多种物质,属于混合物;故选项错误.

C、清新的空气中含有氮气、氧气、二氧化碳等多种物质,属于混合物;故选项错误.

D、大理石中含有碳酸钙、杂质等多种物质,属于混合物,故选项错误.

故选A.

阅读理解

阅读理解。

     Stephen Hawking was one of the most famous scientists in this century. He was born in 1942. he's a

world well-known on space and time.

     Stephen is researching some very big questions, such as: How did the universe begin? How will it end?

Stephen was a student at Oxford University. He studied math and science. Then, at the age of twenty, he

became sick. He was so young, but the doctors said to his family,"He has only two more years to live." As

a matter of fact, the doctors were wrong----he didn't die. He can't walk now but he uses a wheelchair (轮椅).

He can't feed himself and get in or out of bed himself. But he refused to give in to the condition. He talks with

the help of a computer. After Oxford, Stephen went to Cambridge University. Three years later, in 1965, he

became a doctor of philosophy (哲学).

     Because of his serious health problems, it was difficult for him to draw diagrams (图表) or to write. So he

started to think in pictures. With this new way of thinking, he became one of the most famous scientists in the

world. In 1891, he met the Pope(教皇) in Rome. They talked about his ideas. Then in 1988, he wrote his first

important book, A Brief History of Time. It sold more than 5.5 million copies in 33 different languages. He was

once invited to China, he impressed us with his self-confidence, humorous and witty (风趣的) conversation.

1. Which of the following is NOT true?

A. Stephen is good at thinking.

B. Stephen cannot walk.

C. Stephen has had the answers to some very big questions.

D. Stephen had once studied

2. How old was Stephen when he became a doctor of philosophy?

A. 21

B. 23

C. 27

D. 25

3. A Brief History of Time is ________.

A. a book which is well-known all over the word

B. a book about Rome's history

C. Stephen's talk collection with the Pope in Rome

D. Stephen's talk collection with me in China

4. Stephen's studies DO NOT relate (涉及) to ________ according to the passage.

A. science

B. math

C. philosophy

D. art

5. The right order of Stephen's main experiences in ________.

a. He went to Cambridge University.

b. He became very ill.

c. He wrote his first import book.

d. He met the Pope in Rome.

A. c-a-b-e-d

B. a-b-c-d-e

C. c-b-a-e-d

D. a-c-b-e-d

单项选择题