80. It is the farm _____ I used to work when I was at middle school.

　 A. that　　　　 B. which　　　　 C. where　　　 D. in which

79. Do not talk about such things ________ you do not understand.

　 A. that　　　　 B. which　　　　 C. as　　　　 D. where

78. He paid the boy $10 for washing ten windows, most of _______ hadn’t been cleaned for at least a year.

　 A. there　　　 B. those　　　　 C. that　　　　 D. which

77. All _____ I need is a good rest.

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

76. -Would you like to come to dinner tonight?

　 -I’d like to, _____ I’m too busy.

　 A. and　　　　 B. so 　　　　　C. as　　　　　 D. but

75. ________, he lived a very simple life.

A.　　 As Einstein was a great scientist

B.　　 As great scientist Einstein was

C.　　 Great scientist was as Einstein

D.　　 Great scientist as Einstein was

74. Alice was waiting for the bus _______ she noticed a thief running out of a shop.

　 A. when　　　　 B. while 　　　C. after　　　　　 D. as soon as

73. John didn’t do his homework _______ his father came home from work.

　 A. unless　　　 B. while 　　　　C. until　　　　 D. just as

72. . Don't come tonight, I would rather you______ tomorrow.

A. come B. came C. will come D. coming

71. I'll do everything I can______ you.

　　 A. help B. helping C. to help D. be helping