This is a difficult problem to solve.

这是一个很难解决的问题。

youdao

We must arrive before ten o 'clock, this is a difficult problem.

我们必须十点钟以前到达，这是个难题。

youdao

I know this is a difficult problem, but do you prepare to face the challenge?

我知道这是个难题，但是你准备好迎接这个挑战了吗？

youdao

This is a difficult problem.

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And this is a very, very difficult problem -- there is no question -- and it has been a problem that previous Presidents have worked to resolve.

WHITEHOUSE: Press Briefing

Mr. ZOELLICK: This is a devil of a difficult problem.

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