The young man wears glasses because he spends too much time the computer.A. to work inB.

问题补充：

The young man wears glasses because he spends too much time the computer.

A. to work, in

B. working, on

C. to work, on

D. working, in

答案：

A. to work, in

(答案→)B. working, on

C. to work, on

D. working, in

解析：spend用于sb spend...on sth或者sb spend...in doing sth（in可以省略），spend的主语必须是人，可以指花费时间、也可以指花费金钱；在电脑上工作，用介词on，故选B。