1.
Mr. and Mrs. Phuong (offer) have offered free meals for the poor in Ha Noi so far.
2.
We (clean) cleaned up the dirty streets in our area last Sunday.
3.
Have you ever (recycle) recycled things, such as bottles or paper?
4.
My sister (tutor) tutors children from poor families twice a week.
5.
Did you (provide) provide evening classes for sixty children last summer?
6.
I think Mr.Quang (donate) has donated blood several times.
7.
Has Tom (participate) participated in 'Green Summer' programme before?
8.
They (not start) didn't start the community garden project in 2012.
9.
Do your friends (sing) sing for the elderly people every Sunday?