IV. Rewrite the following words in the plural form (Viết dạng số nhiều cảu các danh từ sau).
1. book 2. boy ...........................................3. tomato
4. teacher 5. life ........................................... 6. German
7. watch 8. sheep..........................................9. Frenchman
10. piano 11. child ........................................12. baby
13. photo 14. bench ......................................15. bus
16. box 17. tooth .......................................18. foot
19. Chinese 20. wish ........................................21. brush
22. play 23. ship .........................................24. leaf
25. exercise 26. city ..........................................27. glass
28. man-driver ......................... 29. footballer ................................ 30. class