问题 单项选择题

一列队伍沿直线匀速前进,某时刻一传令兵从队尾出发,匀速向队首前进传送命令,他到达队首后马上以原速返回,当他返回队尾时,队伍行进的距离正好与整列队伍的长度相等。问传令兵从出发到最后到达队尾所行走的整个路程是队伍长度的()倍。

A.1.5

B.2

C.1+

D.1+

答案

参考答案:C

解析:

设部队长是1,部队的速度是a,传令兵的速度是b,传令兵从出发到回到队尾的时候是t,所求量是bt/1=bt,由题意,有以下方程:at=11/(b-a)+1/(b+a)=t把a=1/t代入得:(bt)2-2bt-1=0,解得:bt=1+根号2,故答案为C。

完形填空

三、完形填空

One day a farmer’s donkey fell down into a well. The animal cried   36  for hours as the farmer tried to figure out   37  to do. Finally he decided the animal was   38  and the well needed to be   39  up anyway, so it just wasn’t   40  it to rescue the donkey.

He invited all his   41  to come over and help him. They all grabbed (握起) a shovel (铁铲) and began to shovel   42  into the well. At first, the donkey   43  what was happening and cried horribly. Then, to everyone’s   44 , he was quiet.

A few shovel loads later, the farmer looked   45  the well and was   46  at what he saw. With every shovel of dirt that   47  his back, the donkey was doing something amazing. He would   48  it off and take a step up. As the farmer’s neighbors   49  to shovel dirt on top of the animal, he would shake it off and take another   50  up. Pretty soon, everyone was surprised as the donkey stepped up over the   51  of the well and ran off.

Life is going to shovel dirt on you, all kinds of dirt. The best way of   52  out of the well is to shake it off and take a step up. Each of our   53  is a stepping-stone. We can get out of the deepest   54  just by not stopping, never   55 ! Shake it off and take a step upward!

36. A. sadly                  B. confidently        C. frequently         D. gradually

37. A. how                   B. what                 C. that                   D. which

38. A. strong                 B. old                   C. stubborn            D. powerful

39. A. dug                    B. flowed                     C. covered             D. emptied

40. A. important            B. possible             C. necessary           D. worth

41. A. neighbors            B. relatives            C. partners             D. friends

42. A. dust                    B. pain                  C. stone              D. dirt

43. A. determined          B. recognized         C. realized             D. admitted

44. A. relief                  B. surprise             C. fear                  D. joy

45. A. down                  B. around                     C. for                    D. after

46. A. annoyed                     B. delighted           C. astonished         D. disappointed

47. A. attacked                     B. packed                     C. recovered          D. hit

48. A. shake                  B. blow                 C. take               D. wash

49. A. decided              B. continued          C. pretended          D. volunteered

50. A. base                   B. stage                 C. step                  D. breath

51. A. bottom               B. track                 C. appearance        D. entrance

52. A. holding               B. getting                     C. sorting                     D. sticking

53. A. troubles                     B. happiness          C. successes           D. losses

54. A. reality                B. distance             C. caves              D. wells

55. A. setting up            B. blowing up        C. giving up          D. picking up

单项选择题