1. is -> are
2. does -> do
3. are -> is
5. he's -> his
6. among -> between
7. are -> is
8. front of -> in front of
9. on -> in
10. to -> ∅
11. buy -> to buy
12. bookshelf -> bookshelfs
13. silently -> silent
14. strangely -> strange
15. bear -> bears
16. is -> are
17. aren't -> isn't
18. behind -> between
19. in -> on
20. in front -> in front of
II.
1. Where are the flowers
2. There is a park near Tuan's house
3. The TV is next to the telephone in the lamp
4. The mountains are on the left in the house.
5. What is there behind the house?
6. My school has a big yard
7. Lan watches TV every day
8. What time does she get up?
9. Mr. Quyen teaches English at Yen Nhan secondary school_
10. The students are in the classroom