1. 用所给动词或词组的适当形式填空

1. （1） Don't (talk) in the library.
   

3. （2）        We must   (obey) the school rules and the traffic rules. They're good for our safety(安全).

5. （3） —Can they (eat) in the classroom?
   

   —No, they can't.
   

7. （4） Some students have to (wear) glasses in class because they can't see the blackboard clearly.

9. （5） We (not have to) go to school on May Day（五一节）according to（根据）the law(法律)．