Answers:
1. find → found
2. took → taken
3. located → is located
4. with → by
5. in 2000 by my brother → by my brother in 2000
6. cutted → cut
7. were → was
8. litter → littered
9. helped → is helped
10. in the food → by the flood (câu này sai đề nên mình sửa luôn nha, nếu không sai đề thì trả lời là: in → by)