有三组物质：①NO2和溴蒸气；②乙醛、苯和CCl4三种无色液体；③硫酸铜、碳酸钙

如图所示，运动员挥拍将质量为m的网球击出．如果网球被拍子击打前、后瞬间速度的大小分别为v₁、v₂，v₁与v₂方向相反，且v₂＞v₁．重力影响可忽略，则此过程中拍子对网球作用力的冲量（　　）

A．大小为m（v₂+v₁），方向与v₁方向相同

B．大小为m（v₂-v₁），方向与v₁方向相同

C．大小为m（v₂+v₁），方向与v₂方向相同

D．大小为m（v₂-v₁），方向与v₂方向相同

鸦片战争以后，中国社会逐步沦为半殖民地，主要表现是（   ）

A．中国资源被掠夺

B．中国主权遭到破坏

C．中国封建制度衰落

D．中国自然经济逐步解体

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

高频电缆屏蔽层两点接地，可以显著地降低收发信机入口的干扰电压，保护收发信机的安全运行。

数控车床液压卡盘应定时（），以保证正常工作。

A.擦拭

B.调行程

C.加油

D.清洗和润滑