I must return some books to the library.

我得把一些书还给图书馆。

《牛津词典》

Come on, we must return.

来吧，我们得回去了。

youdao

You must return the book in fifteen days.

你必须在十五天内归还书籍。

youdao

And the constitution says that states must return runaway slaves to their owners.

VOA: special.2009.04.02

Now,he says,people must not permit Haiti's poorest citizens to return to the terrible conditions that existed even before the earthquake.

VOA: special.2010.02.05

It must agree to an amendment to the constitution that would return political balance to North and South.

VOA: special.2009.03.26

"My son says that his mother will come back some day, she must return, " he cried.

BBC: Dhaka building collapse: Factory owners arrested

The athlete also must return his passport within 24 hours after his return to South Africa.

WSJ: Oscar Pistorius's Bail Restrictions Eased

When markets get statistically too far out of whack, they must return to long-term equilibrium.

FORBES: Magazine Article