The boy pretended his homework when his parents came back home.A. to doB. doC. doingD. t

问题补充：

The boy pretended his homework, when his parents came back home.

A. to do

B. do

C. doing

D. to be doing

答案：

A. to do

B. do

C. doing

(答案→)D. to be doing

解析：假装正在做什么，应该用进行时态。