根据句意，用所给单词的正确形式填空。

1．The red sweaters are on __________（sell）．

2．I get up，brush my __________（tooth）and then eat breakfast．

3．Can you tell __________（we）the name of the biology teacher?

4．This is my __________（parent）room．They like it very much．

5．December is the __________（twelve）month of the year．

6．I think you can do it __________（you）．

7．I want __________（buy）a dictionary for my sister．

8．Can he __________（swim）?

9．My brother __________（not have）dessert．

10．How much __________（be）this blue cat?