这是一件艰苦的工作，因此你必须努力去做。

It's a hard work, so you must work hard.

youdao

“你必须努力尝试，”善良的男孩回答说。

"You must try hard," replied the kind-hearted boy.

youdao

你必须努力去创造这种互动性。

You have to work harder to create those interactions.

youdao

And the context of sorting, the worst case is your handed a problem that's in complete reverse order because that implies you have - to do as more work that could possibly-- that you could-- you have to do more work than you would of course if things were in perfect order.

在排序的环境中，最糟糕的情况是待排序的序列是,完全逆序的，在这种情况下,你不得不做更多的工作-,比起一个较理想顺序的序列,你必须花费更多的努力。

哈佛公开课 - 计算机科学课程节选

So you have to try. That's the thing.

所以你必须努力。就是这样的。

就业很难 - SpeakingMax英语口语达人

Now it could be that you're hungry but you're working hard, and so you may not get your food for an hour until after you're hungry.

现在你很饿,但是你必须努力工作,直到一小时后才能吃东西

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选