Mustn't/Needn't

The students mustn't/ needn't bring their books today because they are going to visit the museum.

People mustn't/needn't throw litter on the floor.

We mustn't/needn't shout at each other when we are discussing something. It is very rude.

Jack mustn't/needn't buy another car because he has got three already.

You mustn't/needn't go near that dog. It might bite you.

We mustn't/needn't buy that book. Peter has got the

same book, so he can lend it to us.

I have got plenty of time. I mustn't/ needn't hurry.

Smith gave me letter to post. I mustn't/ needn't forget to post it.

This book is very valuable. You mustn't/ needn't lose it.

It's snowing. You mustn't/ needn't put on your shorts.

You mustn't/needn't cheat at the exams.