对于那些使用恒定的冰川融化的水作为饮用水的数百万人来说，冰川面积不断缩小是一个难题。

Shrinking glaciers are a problem for million is of people who use regular glacier melt for drinking water.

youdao

美国有一个问题，通常只有有钱人家的孩子才能去最好的学校上学，而这实际上是一个难题。

We have a problem in the United States that usually only wealthy kids go to the best schools and it's kind of a problem actually.

youdao

从技术角度看，可伸缩性是一个难题。

As we know from technology, scalability is hard work.

youdao

This is a really interesting system because it also solves a problem for the cell.

这真的是一个有意思的系统,因为它也解决了细胞面对的难题

耶鲁公开课 - 生物医学工程探索课程节选

Think about that for a moment. That's a problem, isn't it?

仔细想想,这是一个难题,不是吗

耶鲁公开课 - 古希腊历史简介课程节选

One of the big problems with studying human diseases is that you can study how they occur in people but there's only a limited amount that you can learn from people.

在人类疾病研究中的一个难题是,你有能力研究发病原因,但以人类为样本做研究却是备受限制

耶鲁公开课 - 生物医学工程探索课程节选