In the past the children were made 15 hours a day.A. to lockB. workC. to workD. lock

问题补充：

In the past the children were made 15 hours a day.

A. to lock

B. work

C. to work

D. lock

答案：

A. to lock

B. work

(答案→)C. to work

D. lock

解析：考查动词make的用法。短语：make sb do 使某人做某事，be made to do sth被迫做某事，make的被动语态要带to,句意：在过去孩子们被迫一天工作十五个小时。 故选C。