－May I go now?

－No, you ________．You ________ stay here．

A．needn’t; have to

B．needn’t; must

C．mustn’t; has to

D．mustn’t; must

－May I go back home now, madam?I really know nothing．

－No, you ________．You ________ stay here till you tell us everything you know．

A．needn’t; haven’t

B．don’t; must

C．can’t; have to

D．mustn’t; had better