61. It was the largest experiment we had ever had; it _____ six hours.

　 A. ended　　 B. finished　　 C. prolonged　　 D. lasted

60. He offered to _____ her a hand as the suitcase was too heavy for her to carry.

A. lend　 B. help　 C. show　 D. loan

59. Carl wanted to play a joke on Bob but gave himself _____ by laughing.

A. away　　 B. in　　 C. out 　　D. up

58. The two dogs started to fight, so we tried to _____ them.

　 A. split　　 B. separate　　 C. tear　　 D. divide

57. The thieves _____ him _____ in the park, took his wallet and escaped.

　 A. held .. back　　 B. held .. up 　C. held .. on　　 D. held .. out

56. As soon as Charles had _____ a little from his surprise, his one thought was to get away.

　 A. returned　　 B. absorbed　　 C. dissolved　　 D. recovered

55. I shall never beat John at tennis; we are clearly not in the same _____.

　 A. set　　 B. band　　 C. group　　 D. class

54. I'm afraid you have no _____ but to come along with us.

　 A. possibility　　 B. permission　　 C. choice　　 D. selection

53. If you put too many potatoes in that paper-bag it will _____.

　 A. fail　　 B. explode　　 C. block　　 D. burst

52. There was a large box behind the door and Peter couldn't _____ falling over it in the darkness.

　 A. help　　 B. resist　　 C. avoid　　 D. prevent