你从图书馆借的书上的戳记表明，这本书必须明天归还。
The stamp in your library book shows it must be returned tomorrow.

去伦敦之前，我必须好好温习一下英文。
I must brush up my English before I go to London.

我必须找人把收音机修理好。
I must get the radio fixed.

孩子用的家具必须经得起拳打脚踢。
Children's furniture must withstand kicks and blows.

这个剧目播出前必须经过数次剪辑。
Before this play is broadcast several cuts must be made.

如果你努力，你就会成功，那必然是真的。
It follows that if you work hard, you will succeed.

无疑，每个结果必定有其原因。
It's certain that every effect must have a cause.

必须得想个办法。
Something must be done about it.