Do you often spend half an houryour homework every day?A. forB. inC. atD. On

问题补充：

Do you often spend half an houryour homework every day?

A. for

B. in

C. at

D. On

答案：

A. for

B. in

C. at

(答案→)D. On

解析：spend+时间+doing sth或on sth表示某人花费多长时间做某事的含义，故本题选D。