Помогите пожалуйста Rewrite the sentences using You mustn't or You needn't.
Example: It isn't necessary to go to school in summer.
Example answer: You needn't go to school in summer.
1) It's forbidden to use the mobile at the exams.
2) It isn't necessary to go to work today. It's Saturday.
3) It's forbidden to be noisy in the library.
4) It's forbidden to walk on the grass here.
5) It isn't necessary to hurry. We have a lot of time.
6) It isn't necessary to buy fruit today. I bought them yesterday.