Вставьте mustn't, needn't, ought to, must.
1.Visitors ... feed animals at the Zoo.
2. You ... buy bread, you've got a lot.
3. You ... take care of your pet.
4. ... I go there? No, you ... .

1. Visitors mustn't feed animals at the Zoo.

2. You needn't to buy bread, you've got a lot.

3. You must take care of your pet.

4.  Ought I go there? No, you oughtn't to.