Tom pretened ---his homework when the teacher came in.

问题描述:

Tom pretened ---his homework when the teacher came in.
A.to be doing B.to do

A
pretend to be doing 是强调不定式的动作正在进行的过程中.
pretend to do是强调假装要做某事,而不一定正在进行或者是已经发生.
还有一种完成式pretend to have done 强调假装后面的动作已经完成.
pretend to be reading就表示他假装正在读书
pretend to sleep 表示他要去睡觉