问题 选择题

在探究“电流做功的多少与哪些因素有关”的实验中,通过观察电动机提升物体上升的高度来判断电流做功的多少。这种研究问题的方法叫“转换法”。下列探究中使用了“转换法”的是

A.探究电流的热效应时,通过观察温度计示数升高的多少来反映电流通过导体产生热量的多少

B.探究串联电路的电阻关系时,用一个电阻去代替两个串联电阻,使电路中电流大小不变

C.探究不同物质的导电性能时,将不同的物体接入相同电路,观察接入不同物体后电路中小灯泡的亮度或电流表的读数

D.探究通过导体的电流与导体电阻的关系时,要保持导体两端的电压不变

答案

AC

题目分析:转换法是中学物理中把直接测量有困难的量转换成便于测量的量来研究的一种重要的研究方法,也就是借助某些物体的特性来研究看不到或不易观察到物质,形象直观。

A、探究电流的热效应时,通过观察温度计示数升高的多少来反映电流通过导体产生热量的多少,属于转换法; 

B、探究串联电路的电阻关系时,用一个电阻去代替两个串联电阻,使电路中电流大小不变,属等效替代法;

C、探究不同物质的导电性能时,将不同的物体接入相同电路,观察接入不同物体后电路中小灯泡的亮度或电流表的读数,属于转换法;

D、探究通过导体的电流与导体电阻的关系时,要保持导体两端的电压不变,属于控制变量法.

故选AC。

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)

Once there was a very brilliant, creative and educated man. He gained much   36   while traveling throughout the world. Unfortunately he lost his legs and left arm in a tragic accident, leaving only a finger and thumb on his right hand. He became so   37   that he was afraid he would spend his life   38   and would no longer be able to use his life in a(n)   39   way.

One day, he remembered how he had always loved getting   40  . He realized that he still had partial   41   of his right hand and could write with   42  . Then, he had an idea. “Why not write to other people who need encouragement?”

He   43   where he could find those who could be encouraged if they read his letters. He thought of people in   44  . Many of them had hope of regaining their   45  . Others would keep feeling depressed and remain put away for the rest of their lives. He decided that he must try to   46   them. So he wrote to a prison ministry about sending letters to the prisoners. The prison minister replied that writing to the prisoners would be   47  . However, it would be against prison rules for the prisoners to write back.

48   with the intention, the man began sending   49   messages of God’s love, hope, strength, and encouragement. He wrote twice a week, testing his strength and ability to the   50  . He poured his heart and soul into his words,   51   his experience, sense of humor, optimism, and faith.

It was difficult to write those letters, especially without hope of any   52  . Frequently, he felt discouraged, wondering if anyone   53    read his letters. However, this was his   54   chance,so he determined to continue.

At last, he received a letter from the prison officer, which said, “Please write on the best paper you can afford. Your letters are passed from cell (牢房) to cell until they almost fall to   55  !”

We all have unique experiences, abilities and talents. We can discover ways to reach others in need of encouragement and strength.

36. A. wealth             B. faith      C. experience  D. confidence

37. A. depressed            B. embarrassed       C. ashamed       D. thrilled

38. A. writing        B. suffering       C. weeping      D. wandering

39. A. abnormal            B. regular          C. comfortable       D. meaningful

40. A. presents        B. e-mails          C. letters    D. prizes

41. A. sense              B. strength         C. shape        D. function

42. A. affection            B. caution          C. difficulty       D. confidence

43. A. estimated       B. doubted         C. assumed         D. wondered

44. A. hospitals            B. churches        C. prisons        D. charities

45. A. families            B. letters     C. freedom         D. conscience

46. A. release             B. reach         C. defend          D. know

47. A. acceptable      B. reasonable  C. prohibited       D. considered

48. A. Faced             B. Filled         C. Satisfied    D. Impressed

49. A. holy              B. daily          C. one-way     D. round-way

50. A. point              B. worst         C. degree       D. limit

51. A. sharing             B. learning        C. gaining       D. enriching

52. A. success             B. reply          C. help           D. progress

53. A. curiously            B. patiently        C. carefully       D. actually

54. A. only              B. better           C. extra         D. lost

55. A. ruin               B. pieces     C. the ground  D. the bottom

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