You have to be over 16 to bet.

赌博者年龄不得低于16岁。

《牛津词典》

Why do you have to be so untidy?

你为什么非得这么邋遢？

《牛津词典》

The posts have to be set in concrete.

这些柱子必须固定在混凝土中。

《柯林斯英汉双解大词典》

You don't have to be a VIP celebrity." Some experts say famous people may bring public awareness to an issue.

VOA: special.2009.05.08

Now we don't have to be overly concerned here with what I take to be Chudleigh's generous oversight of Milton's generally sexist bias.

这一点我们不必多虑,弥尔顿总体上有性别歧视，恰德莱大方的忽视了这一点。

耶鲁公开课 - 弥尔顿课程节选

so that if you come up with some amazing invention, you have to be able to tell all the people about it.

这样如果你要是有了什么了不起的发明，你要能够把它告诉别人。

沟通很重要 - SpeakingMax英语口语达人

All cash donations have to be backed up by a record under the new law.

FORBES: Cutting Taxes While Doing Good

So therefore all of the candidates will have to be very competitive with African-Americans this year.

NPR: Presidential Candidates Target Black Music Festival

Ratings would have to be confidential to prevent investors from free-riding on each other.

FORBES: Rethinking Credit Ratings