This is a big problem in poor countries.

VOA: special.2010.02.24

This is a big problem. -Interesting.

这可是个大问题，-挺有趣。

普林斯顿公开课 - 人性课程节选

A big problem with this is a lot of Freudian theory is claimed to be validated in the course of psychoanalysis.

这里存在的一个大问题便是,精神分析理论中的很多内容,被认为是能够在精神分析的过程中,得到证实的。

耶鲁公开课 - 心理学导论课程节选

Taking the problem, recognizing that you know what, 8 even though this is a pretty big problem size 8 in this case and last time it was size 8 or in the case of the papers in size of a thousand roughly with the phonebook, I assume these are in a perfectly straight line they won't quite fit.

以这个问题为例，你们要认识到，在这种情况下，这是个比较大的问题，其大小是,上次它的大小也是8，但在纸片那个问题中,电话簿的规模大概是上千的，现在假设这些,杯子完全在同一条直线上，虽然并不十分符合这个条件。

哈佛公开课 - 计算机科学课程节选