31-35CDBDB 36-40 BAACD 41-45ADBBA
46-50 ACDBA 51-55 DBAAD 56-60 ABBDA
66. to→into 67. problems后加with 68. adventure→adventures
69. for→of 70. deserts→deserted 71. does→did 72. with→about/over 73. by→to 74. 去掉a
76. He has many interests, such as listening to music, playing football and surfing the Internet.
77. In order to learn English better, she developed a friendship with an American girl.
78. John is honest and brave, so is his brother.
79. Mary said that she enjoyed reading very much, but her sister was into classical music.
80.We were watching a wonderful basketball match when the light went out.