=>

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.

-> last Sunday (QKĐ, S V2/ed)

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 vật, người)

6. When did you start working for this charitable organization?

-> start Ving : bắt đầu làm gì