77. Small sailboats can easily turn over in the water ______ they are not managed carefully. 2007上海

　 A. though　 　 B. before　　 C. until　　 D. if

76. We had to wait half an hour ______ we had already booked a table (2007辽宁.)

A. since 　B. although 　C. until 　D. before

75. Leave your key with a neighbor ___　 you lock yourself out one day.　 2007北京

A. ever since　 B. even if　　 C. soon after　　　 D. in case

74．________I really don’t like art, I find his work impressive. 2007山东

A．As 　　B．Since 　C．If 　D．While

73. I won’t call you, ________ something unexpected happens. 2007 海南

　 A. unless　　　 B. whether　　　　 C. because　　　　 D. while

72. My parents live in a small village. They always keep candles in the house _____ there is a power out.

A. if　 　 　B. unless　　　　　　　 C. in case　　　　　　　　　　 D. so that 　　　2007重庆

71. Many of them turned a deaf ear to his advice, _______ they knew it to be valuable. 2007浙江.　

A. as if　　　　 B. now that　　　 C. even though　　　 D. so that

70. Pop music is such an important part of society ______ it has even influenced our language. 2007上海　

　A. as　 B. that　　 C. which D. where

69. Most birds find it safe to sleep in the trees, but ________ they have eggs or young chicks, they don’t use a nest. 2007湖南　 　A. why　　　　　　 B. how　　　　　　 C. unless　　　　　 D. where

68. In my opinion, life in the twenty-first century is much easier than ________.2007安徽

A. that used to be　 　　　 B. it is used to　　　　　　　 C. it was used to　 　　　 D. it used to be