There must be some mistake, stammered Bob.

“一定是搞错了，”鲍勃结结巴巴地说。

There must be a thief at school, said Tapiwa.

“学校里一定有个小偷，”塔皮瓦说。

There must be someway to fix this issue.

一定有某种方式可以解决这个问题。

The researchers believe there must be lots of salts in the underground lake.

研究人员认为，地下湖中一定有大量的盐。

There must be some kind of explanation.

肯定有某种解释。

We thought there must be something wrong because we hadn't heard from you.

我们认为一定有什么事不对劲，因为我们没有你的消息。

There must be contests, and we must win.

那里一定有竞赛，我们一定要赢！

We must be well prepared; there must be no slips.

我们必须准备好，一定不能有任何闪失。

There must be many new motors there.

那里一定有很多新马达?。

There must be the balance.

这其中必须要有平衡。