I helped my mother_____【clean】 up all the rooms yesterday.

用所给单词适当形式填空
I helped my mother_____【clean】 up all the rooms yesterday.
Ecah of us____【be】in the classroom now.
应填：
(to) clean
is
注：help sb （to） do sth 帮助某人做某事
to 为不定式符号,可以省略
each of …… 做主语时,谓语动词用单数形式help sb with sth和help sb do sth的区别是什么？