You had better finish your homework.A. doB. doingC. to doD. done

问题补充：

You had better finish your homework.

A. do

B. doing

C. to do

D. done

答案：

A. do

(答案→)B. doing

C. to do

D. done

解析：此题考查固定结构finish doing sth表示做完某事。