问题 填空题

物理知识在生产和生活中有着广泛应用,利用______ 知识可以鉴别物质;刀刃磨得锋利,是为了减小接触面积,以便用较小的力就能产生很大的______,易于割开物体;锅炉上的液位计应用了______原理;实验室和生产技术中广泛使用的液体密度计是应用______原理的典型例子.

答案

①利用密度 知识可以鉴别物质;

②刀刃磨得锋利,这是在压力一定的情况下,减小接触面积,从而能产生很大的压强;

③锅炉水位计和锅炉就构成了一个连通器,水不流动时,液面就是相平的,液面就保持在同一水平面上,我们通过观察水位计中水位的高低就可以知道锅炉中水的多少,及时加水.

④密度计的设计利用了物体的浮沉条件,让密度计在液体中漂浮,根据物体的浮沉条件可知,漂浮时F=G,物体的重力不变,浮力就不变;根据阿基米德原理FgV可知,液体的密度越大,密度计排开液体的体积就越小.

故答案为:密度;压强;连通器;阿基米德.

完形填空

第二节:完形填空(共20小题;每小题1.5分,满分30分)

An old man was going home late one night with his horse and cart after a hard day’s work. When he was not far from his   21   , the light on the cart went out. He tried to make the lamp     22     again, but he could not.

So he went along the road     23     a light. But a policeman saw the   24    without a light. He     25    the old carter(赶车人).

“No one     26     take a cart along a road at night without a light, ”said the policeman. “You’ve     27     the law. ”

“I    28     a light, but it has just gone out. ”

“I don’t believe that    29   ,” said the policeman . He took out a book and got     30    to write. “What’s your     31     and where do you live?”

“Please don’t take my name, ”said the man. “My house is just over    32     . I haven’t come far without a light. ”

“You came all     33    without a light. What’s your name?”

The carter quickly took the policeman’s hand and put it down hard on the     34     of the lamp. The lamp was still     35    , and it     36    the policeman’s hand. He     37     and he was very angry.

“Now what do you think?” said the carter. “Did I come all the way without a light?”

“No,”said the policeman, “I     38    you now. But I still     39     to know your name. You’ve broken the law now. You’ve burnt a policeman’s hand. So you must come with me to the police station. You’ll be there all     40   . ”

21. A. field     B. family     C. house       D. land

22. A. burning       B. lighting      C. lighted            D. burn

23. A. with     B. without      C. by           D. on

24. A. cart      B. carter     C. the old man        D. house

25. A. caught  B. kept       C. called       D. stopped

26. A. may     B. can        C. might       D. should

27. A. kept     B. observed    C. broken            D. jumped

28. A. have     B. had        C. has had       D. were having

29. A. lies       B. story      C. word        D. remark

30. A. angry   B. excited       C. prepared      D. ready

31. A. name    B. number      C. job          D. family

32. A. here     B. that        C. there        D. this

33. A. the time       B. the way      C. the night     D. by yourself

34. A. side      B. face       C. top          D. surface

35. A. bright   B. dark       C. warm       D. hot

36. A. hurt      B. burnt     C. injured            D. wounded

37. A. jumped B. screamed    C. walked        D. ran

38. A. free      B. trust       C. know       D. believe

39. A. like      B. want      C. hope        D. expect

40. A. year     B. month     C. day          D. night

单项选择题