You must copy it now.
你必须现在就去复印。
I must finish my homework tonight.
我今天晚上必须完成我的家庭作业。
I'm afraid I must stop him.
恐怕我必须要阻止他了。
You must give it back to me tomorrow.
你明天必须把它还给我。
You mustn't stay with him.
你不能跟他呆在一起。
You must be tired.
你一定是累了。
It must be very interesting to go to Disney World.
到迪斯尼去一定很有趣。
I must say, it is a good idea.
我不得不说这是一个好主意。