问题 选择题

When he is free, he often helps his parents ________ some housework.

A.does

B.do

C.doing

D.did

答案

答案:B

题目分析:句意:当他有空时,他经常帮助他的父母做家务。help sb (to)do sth意为“帮助某人做某事”,其中可以省略to;故选B。

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