=>
1. Last year we started a community garden project.
-> last year (QKĐ, S V2/ed)
2.  So far, we have asked people to donate books and clothes to the poor children.
-> so far (HTHT, S have/has V3/ed)
3. Because the lake was full of rubbish, they decided to clean it up last Sunday.
-> because S V : bởi vì
4. Green Summer was organized for the first time in 1997.
-> bị động QKĐ was/were V3/ed
5. Go Green is a non-profit organisation that protects the environment.
-> that (đtqh chỉ người, vật)
6. When did you start working for this chartiable organization?
-> start Ving : bắt đầu làm gì