问题 选择题

用分子的观点对下列常见现象的解释中不正确的是(  )

A.花香四溢--分子不停地运动

B.酒精挥发--分子间间隔变大

C.食物腐败--分子本身发生变化

D.热胀冷缩--分子的大小随温度变化而变化

答案

A、花香四溢是因为分子不停地运动,花的香气分子运动到空气中,进入人们的鼻孔,正确.

B、酒精挥发是因为分子不断运动,造成分子间间隔变大,正确.

C、食物腐败发生了化学变化,生成了其他物质,构成物质的分子本身发生变化,正确.

D、热胀冷缩是因为分子的间隔随温度变化而变化,分子本身大小不变,此项说法错误.

故选D

阅读理解

阅读理解。

     In life, people come across many experiences, which they remember throughout their lives. I had a similar

experience, too.

      I was very excited. It was the day of my last paper of the final examination. My mind was full of thoughts

of how I would spend my vacation. I was especially excited of the invitation that my uncle had given me to stay with him for a few days in Cambridge.

     I was prepared for the subject, physics. My friends and I were on the ground doing the last minute revisions and also discussing the questions that were supposed to come in the paper. Suddenly the bell rang and we got

into our classrooms. The teacher came and quickly handed out the answer paper and the question paper. The

paper was of two hours and some of the expected questions came. I finished it almost forty-five minutes earlier. But since it was a rule not to collect the answer paper before the allotted (规定的) time. the teacher was not

collecting and I had to sit till the time was over. I checked my paper twice and corrected some of the mistakes

in it. I started thinking about the place my friends and I had planned to go after the paper.

     Though I was thinking for a long time, the time seemed to be endless. So I thought of drawing something

on the question paper and turned it overleaf. I was shocked to see that the page which I had supposed to be

blank had four more questions on it which carried 20 marks and would take at least half an hour to complete.

I had a quick glance at my watch. There were only 10 minutes left. I was so nervous that I was hardly in a

state to write anything. They were the sub-questions (小题) of the last question. Suddenly our physics teacher

came in and told all of us that in the last question, out of 6 sub-questions only 2 had to be solved. I felt very

much relieved.

      Thereafter I never made such mistakes again. But I realized that my anxiousness and excitement could

have cost me to lose 20 marks and decided never to make such a mistake again.

1. Which of the following statements is true?

A. The writer didn't work hard at physics.

B. The writer lost 20 marks for the last question.

C. The writer made some mistakes during the exam.

D. The questions on the paper were difficult for the writer.

2. The underlined word "relieved" means ________.

A. more nervous

B. less afraid

C. more surprised

D. less worried

3. We can infer from the passage that _______.

A. the writer did 2 sub-questions of the last question

B. the writer turned overleaf to do the sub-questions

C. the writer spent 45 minutes finishing the paper

D. the writer got full marks in the physics exam

4. We can learn from the passage that we should _______.

A. learn some exam skills

B. concentrate on what we are doing

C. try our best to do well in the exam

D. be careful not to make mistakes in the exam

填空题