四、用所给单词的适当形式填空。
1. People often ______ (plant) trees on Planting Trees Day.
2. Can you ______ (smell) the smoke from there?
3. There ______ (be) a lot of rubbish in the water last year.
4. What ______ (make) the river dirty?
5. The streets become very ______ (mess).
6. Look! Who ______ (make) toy bears?
7. Uncle Wang ______ (smoke) in the room. There was a lot of smoke.
8. Can you pick ______ (they) up?

plant
; smell
; was
; makes
; messy
; is making
; smoked
; them

五、按要求改写句子。
1. We can go to school by metro.（改为同义句）
We can ______ ______ ______ to school.
2. Yang Ling likes living in the city.（对画线部分提问）
______ ______ Yang Ling ______ living?
3. The room is messy.（改为感叹句）
______ ______ messy room!
4. They are walking to the park after school.（改为一般疑问句）
______ ______ walking to the park after school?
5. Toys make the room messy.（对画线部分提问）
______ ______ the room messy?

take
; the
; metro
; Where
; does
; like
; What
; a
; Are
; they
; What
; makes