mustn't needn't

mustn't needn't
mustn't needn't

mustn't needn't
mustn't----------------不准,不许可
needn't ---------------不必

mustn't 不准
needn't 不必

mustn't 不准 ，禁止　　needn't 不必，不需要

mustn't不可以，不允许，不准
needn't不必，不用