You must be late tomorrow.

你明天一定会迟到。

Oh! You must be very tired.

哦！你一定很累。

You must be having a great time!

你一定玩得很开心！

You must be careful of falling stones.

你必须小心掉落的石头。

Get him his change? You must be joking.

给他找零钱？你一定是在开玩笑。

And you must be careful of falling stones.

你们必须小心落石。

You must be excited about coming to China soon.

你一定很期待很快来中国吧。

You must be excited about leaving for China tomorrow, Steve!

你一定很兴奋明天要去中国了，史蒂夫！

In Britain, you must be seventeen or over to drive a car.

在英国，你必须年满十七岁才能开车。

First of all, you must be intelligent enough to get a related college degree.

首先，你必须足够聪明才能获得相关的大学学位。