79. If we want to protect the environment, we must __________ the problems and convince people to take action.

A. communicate　　 B. compare　　　　 C. conclude　　　　 D. clarify

78. Knowledge is like money. By ____________ it can increase in quantity as well as in value.

A. circulating　　　 B. clarifying　　　 　C. calculating　　　 D. collecting

77. As violence and crimes are on the rise all across the world, it is only wise to ________ a place where we are going to be safe.

A. check　　　　 B. choose 　　　　　　C. circulate　　　　 D. clarify

76. Plastic bags are even dangerous to wildlife as thousands of sea animals are killed each year when they eat or are _________ by them.

A. chewed　　　 B. cheated　　　　　 C. choked　　　　 D. classified

75. He _________ over the problem for several days before making his decision.

　 A. checked　　　 B. chewed　　　　　 C. catered　　　　 D. choked

74. --- Julia said she sent you a birthday card yesterday. Have you got it?'

　 　--- Oh, really! I haven't __________ my mailbox yet. (2005年高考天津卷)

　 　A. examined　　　 B. calculated　　　　 C. tested　　　　　 D. checked

73. Schools ban students from bringing mobile phones, which are used to _______ in exams.

　 　A. cheat　　 　　　B. boycott　　 　　　C. charge　 　　　　　D. click

72. She was complaining that the doctor was _________ too much for the treatment he was giving her．

A. spending　　 　　B. offering　　　　 C. costing　　 　　　　D. charging

71. Every year on 28th, September, many people gather in Qufu to _________ Confucius's birthday, paying their respects.

　　A. celebrate　　　 B. calculate　　　 　C. congratulate　　 　D. welcome

70. I don’t think he is a good writer; he specially writes books to ________ to low tastes.

　　 　A．blame 　　　 　B. cater　　　 　 　　　C. cancel　 　　　　D．charge