问题 单项选择题 案例分析题

已知发电机额定电压10.5kV,额定功率20MW,功率因数0.8,最大负荷利用小时Tmax=3200h。发电机引出线三相短路电流数据为I″=28kA,Itk/2=22kA,Itk=20kA。短路电流冲击系数为1.8。继电保护动作时间为0.1s,断路器全开断时间为0.2s。三相母线水平布置,绝缘子跨距1.2m,相间距离0.7m,周围环境温度28℃。以此为条件,回答下列问题。

查表相间截面系数()。

A.1/6bh2

B.1.44b2h2

C.0.333bh2

D.0.5bh2

答案

参考答案:C

完形填空

It was the night before the composition was due. As I looked at the list of topics(题目), “The Art of Eating Spaghetti(意大利面条)” caught my eye. The word “spaghetti” brought back the ___36___ of an evening at Uncle Alien’s in Belleville ___37___all of us were seated around the table and Aunt Pat ___38___ spaghetti for supper. Spaghetti was an exotic(外来的) treat in ___39___days. Never had I eaten spaghetti, and ___40___ of the grown-ups had enough experience to be___41___it. What laughing ___42___ we had about the___43___respectable method for moving spaghetti from plate to mouth. ___44___, I wanted to write about that, but I wanted to ___45___ it down simply for my own ___46___,  not for Mr. Fleagle, my composition teacher. ___47___, I would write something else.

When I finished it the night was half gone and there was no ___48___ left to write a proper com­position for Mr. Fleagle. There was no choice next morning but to ___49___my work. Two days pas­sed before Mr. Fleagle returned the ___50___ papers. He said, “Now, class, I want to read you a composition, ‘The Art of Eating Spaghetti’. ”

My words! He was reading my words out ___51___ to the whole class. ___52___ laughed, then the whole class was laughing with open-hearted enjoyment. I did my best not to show___53___, but what I was feeling was pure happiness, ___54___ my words had the power to make people___55___.

36. A. memory       B. thought      C. knowledge  D. experience

37. A. when    B. where C. since   D. after

38. A. cooked B. served C. got     D. made

39. A. their     B. past    C. last     D. those

40. A. none     B. one     C. earns   D. neither

41. A. careful about       B. good at      C. fond of      D. interested in

42. A. speeches      B. lessons       C. sayings       D. arguments 

43. A. nearly   B. naturally    C. officially    D. socially

44. A. Especially    B. Probably    C. Suddenly    D. Fortunately

45. A. settle    B. put     C. bite     D. let     

46. A. work    B. story   C. luck    D. joy

47. A. However      B. Therefore   C. As for him  D. Except for that 

48. A. time     B. excuse C. way    D. idea   

49. A. give up B. continue     C. hand in      D. delay 

50. A. written B. graded       C. collected    D. calmly

51. A. laid      B. fast     C. publicly     D. calmly

52. A. People  B. Nobody      C. Somebody  D. I

53. A. shock   B. wonder      C. worry D. pleasure

54. A. if  B. for      C. while  D. although

55. A. excited B. satisfied     C. think   D. laugh 

单项选择题