Now the computers are more and more people all over the world.A. used forB. discovered by

问题补充：

Now the computers are more and more people all over the world.

A. used for

B. discovered by

C. used by

D. discovered for

答案：

A. used for

B. discovered by

(答案→)C. used by

D. discovered for

解析：C “现在，电脑被全世界越来越多的人使用。”“被......使用”be used by...；used for“被用作......”；discovered by“被......发现”。故选C 。