The work must be completed within a certain time limit.

这项工作必须在一定期限内完成。

《牛津词典》

Some part of the work must be done by ax.

部分活儿必须用斧头完成。

youdao

For the people of Afghanistan, and for our Shared security, the work must be done.

为了阿富汗人民和我们共同的安全，这项工作我们义不容辞。

youdao

Now,for this business to work, we must be able to produce a charming widow, with or without the beauty, as advertised."

VOA: special.2010.04.24

So, the total work that we can get out must be zero, out of the whole sum of them.

因此，我们可以从这两个热机,得到的总功，一定是零。

麻省理工公开课 - 热力学与动力学课程节选

It makes sense, right, because you know we got less work out and delta u is the same right, so it must be that less heat got transferred.

这是显而易见的，因为输出的功更少,且Δu相等，所以需要的热量更少。

麻省理工公开课 - 热力学与动力学课程节选

In the work ahead, we must be guided by the philosophy that made our Nation great.

NPR: Text of Bush's State of the Union Address

"It's going to happen by doing the careful work that must be done in a thorough investigation, " Patrick said.

NPR: Image Leads To Hunt For Boston Bombing Suspect

But I have every confidence that if we are willing to continue doing the difficult work that must be done -- by each of us and by all of us -- then we will leave this struggling economy behind us, and come out on the other side, more prosperous as a people.

CNN: Obama's remarks on signing the stimulus plan