1、  He is badly ill. We must _________ a doctor at once.

2、  There are about fifty students in the class. Mike is _________ tallest.

3、  As winter comes, the weather is getting _________.

4、  My mother has never been to London, _________?

5、  —I can’t find my handbag!

6、  Would you please buy some milk, William? There _________ in the fridge.

7、  The river is the second _________ one in the town.

8、  —Must I finish the work today, Mr. Wang?

9、  —Excuse me. Do you have a table for two?

10、  The nearest hospital is about fifteen _________ walk from here.

11、  —Someone is knocking at the door. Who may it be?

12、  He is so careful to _________ there are no mistakes in his homework.

13、  —Have you ever known Tom before?

14、  —Must I go with them tomorrow?

15、  This task is too difficult. We’d better turn _________ the teacher for help.