is that a box改成複數

Are those boxes？

RELATED INFORMATIONS

1. That is his brother的複數形式
2. It is a photo（改為複數句）
3. 完成句子1.This is a photo.（改為複數）_______ _______ ________photo 是_________ _____________photo.
4. this is a bus.【變為複數句】
5. whose coat it is？
6. 變複數Whose knife is this？It‘s Peter’s.——————————————————————
7. it is的複數
8. It is a watch.（改為複數形式）
9. that is her pencil—box（改複數句）
10. That is a box改為單數或則複數
11. 將下列句子變為複數句Is this a new shoe？Is that a pencil_box？She doesn't work on Subday It is not a watch. The child is singing happily.
12. This is my pencil（變為複數句）
13. this is a pencil改為複數句
14. 句型轉換.1.This is a pencil- box.（改為複數句）_______ ______ ______pencil-boxes. 2.Are you Miss Gao？（做否定回答）____，____ ____.3.The twins come from Japan.（改為同義句）The twins ____ ____Japan.4.I don't know how I can look after my dog.（改為同義句）.I don't know how ____ ____ ____my dog.5.Mr Green is from __the USA__.（對劃線部分提問）____ ____Mr Green ____？
15. Is that his class？怎麼變成複數形式？
16. That is his book.怎麼改為複數句
17. that is his brother改為複數句
18. that is a pencil.改為複數句
19. 不可數名詞是不是永遠都不可能用複數形式.（-s）比如水，永遠都不會出現waters這種情況？還有”cloud”是不是可數名詞，我覺得是不可數，但怎麼新概念第一册書上有”There are some clouds in the sky，but the sun is shining.”
20. suggestion有複數形式麼還是不可數名詞？