题目

A survey _______ in 2002 by the Computer Security Institute, a private organization in the USA, showed that 90 percent of the 503 biggest companies and government departments questioned _______ their security systems _______ into in the previous year. A. conducted ; had ; broke                      B. conducted; had had ; broken C. was conducted ; had had ; broken       D. to be conducted; had ; broke 答案：B

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