Lời giải đây nhá:
1. I have never painted a muaral over graffiti before.
2. Mr. Binh has started recycling for two years.
3. Because David was lazy, he failed the exam.
4. It's five months since last cleaned up the street.
5. We began donating books and clothes ten years ago.
Chúc bạn học tốt nha!!:))