1. 用所给词的适当形式填空

1. （1） It's cold here．Please keep the door  (close)．
   

3. （2）   (sudden)，we heard a loud noise outside the classroom．

5. （3） He went to bed and soon fell  (sleep)．

7. （4） While I  (watch)TV，my parents went out．

9. （5） When I walked past the classroom，I saw Liu Ying  (read)a book．