1·In itself, it's not a difficult problem to solve.
这本身并不是个难解决的问题。
—— 《牛津词典》
2·How to improve the quality of products was a difficult problem to him.
如何提高产品质量对他来说可是个难题。
3·Extracting heat from very hot, dry rocks presents a more difficult problem: the rocks must be fractured to permit the circulation of water, and the water must be provided artificially.
从极热的而干燥的岩石中提取热量，暴露出了一个更加困难的问题：必须击碎岩石以保证水的循环，而水必须是人工提供的。
4·She is working at a difficult problem in mathematics.
她在做一道数学难题。
—— 《新英汉大辞典》
5·It's really a difficult problem.
这真是个难题。
6·At first there was a seemingly difficult problem.
在开始的时候存在一个难题。
7·Never have I come across such a difficult problem.
我还从没有遇到过这样困难的问题。
8·He soon turned his attention to the difficult problem.
他很快把注意力转到这个难题上。
9·The greatest scholar cannot solve this difficult problem.
再伟大的学者也没有办法解答这个难题吧。
10·Fortunately, it's not a difficult problem (see Listing 6) to fix.
所幸的是，这个问题不难解决(见清单6)。
1·How to improve the quality of products was a difficult problem to him.
如何提高产品质量对他来说可是个难题。
2·She is working at a difficult problem in mathematics.
她在做一道数学难题。
—— 《新英汉大辞典》
3·Even though these economies are only just starting to feel the upturn, policymakers now face a difficult problem: how to sustain a robust recovery without blowing up bubbles.
尽管这些经济体的经济刚开始好转，但政策制定者现在面临难题：在避免经济泡沫的情况下如何保持经济的强劲反弹。
4·He soon turned his attention to the difficult problem.
他很快把注意力转到这个难题上。
5·Providing dynamic internationalization of information for display is a difficult problem.
为显示提供信息的动态国际化是一个难题。