问题 选择题

传感器是把非电学量(如温度、速度、压力等)的变化转换为电学量变化的一种元件,在自动控制中有着相当广泛的应用.如图是一种测量液面高度h的电容式传感器的示意图.从电容C大小的变化就能反映液面的升降情况.关于两者关系的说法中正确的是(    )

A.C增大表示h减小

B.C减小表示h增大

C.C减小表示h减小

D.C的变化与h变化无直接关系

答案

答案:C

题目分析:电源接通时,电容器的电压一定,若电容C减小时,金属棒与导电液的正对面积减小,所以h减小.

故选C

点评:根据电容的定义公式电容的决定因素进行综合分析.

单项选择题
完形填空

第二节 完形填空(共20小题;每小题1分,满分20分)

请认真阅读下面短文,从短文后各题所给的A、B、C、D四个选项中,选出最佳选项,并在答题卡上将该项涂黑。

Think you can’t be happy? You’ll think again after reading this story.

Barbara Ann Kipfer hated her feet. They were too big and she always seemed to   36   over them when someone was   37   —usually a smart guy. Come to think of it, her teeth were too big, too. The other kids teased her because of the way she   38   and because she wanted to be a sportswriter some day. No matter what she did, she was teased for being “  39  .”

That’s   40   she started writing down things that she liked in a notebook. “It was like a friend, and it   41   me that there are good things,   42   everything around me is unpleasant,” she says. She copied the list over and over,   43   new things every day.

One day, she decided to   44   her list with some of the girls in her class, hoping they would think it was as much fun as she did. But   45  , they made her feel stupid again. “They laughed at me,” she remembers, “I was ashamed, and I   46   doing it.” Here comes the  47  part. When she was in 10th grade, Kipfer found her old notebook and decided to   48   where she left off. “It was like a diary, like a photograph of my life,” she says. She started writing to publishers, asking them if they’d be interested in printing her list as a book.

She kept writing to one company   49  , because she liked the types of books it printed. “He kept saying, ‘It’s just a list, what am I supposed to do with it?’” “You’re not   50   to do anything with it. It’s   51   supposed to remind people of something they did that was really  52  .”

Finally, the publisher   53   to turn Kipfer’s list into a book, which sold more than million copies! 14,000 Things to Be Happy About even   54   it to be New York Times Best Sellers list.   55   being a best-selling author, Kipfer also went to realize her dream of becoming a sports editor at the Chicago Tribune.

36. A. jump                         B. fall                          C. turn                         D. push

37. A. nearby                       B. around                            C. watching                  D. laughing

38. A. dressed                      B. lived                        C. thought                    D. looked

39. A. foolish                      B. special                            C. different                   D. shy

40. A. what                         B. when                       C. because                    D. where

41. A. reminded                   B. told                         C. persuaded                 D. helped

42. A. because                            B. but                          C. unless                      D. even though

43. A. adding                       B. finding                     C. making                    D. giving

44. A. talk                           B. discuss                     C. share                        D. write

45. A. then                          B. naturally                  C. further                            D. instead

46. A. continued                  B. stopped                    C. enjoyed                    D. hated

47. A. cool                          B. important                 C. exciting                    D. funny

48. A. find out                            B. pick up                    C. think of                    D. give up

49. A. in general                  B. at first                      C. in particular              D. at last

50. A. made                         B. going                       C. advised                    D. supposed

51. A. often                         B. just                          C. also                         D. always

52. A. excellent                    B. successful                 C. fun                          D. true

53. A. hoped                        B. agreed                      C. refused                     D. considered

54. A. made                         B. expected                  C. hoped                      D. helped

55. A. Without                            B. Instead of                 C. While                      D. Besides