Ответ:

1a. Which grammatical structures do we use to...

1. express obligation or necessity: must; have to; need to; need

2. say there is no obligation or necessity: mustn't; don't have to; needn't; don't need to

3. say something is prohibited or not possible: aren't allowed to; can't

4. give advice or recommendations: ought to; should; had better

2. Correct these sentences

1. You mustn't give false information...

2. Do you have to sign...

3. You needn't open...

4. She had better had a credit...

5. We ought to ask for...

6. Students don't need to have a bank...

Объяснение: