Computersin offices and homes since 1970sA. have been usedB. had been usedC. was D. has b

发布时间：2020-08-17 02:22:22

Computers    in offices and homes since 1970s．
A. have been used
B. had been used
C. was
D. has been used

网友回答

(答案→)A. have been used
B. had been used
C. was
D. has been used
解析：考查时态和语态。从时间状语since 1970s要使用现在完成时，且puters与use之间为被动关系，故选A。句意：自20世纪70年代以来，电脑已经在家庭和办公室使用。
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