Well, I talked about the problem of using plasmids in gene therapy, that it's very difficult to get them into cells.

我们之前讨论过,基因治疗中运用质粒的问题,质粒本身极难进入细胞

耶鲁公开课 - 生物医学工程探索课程节选

That it is intended as a kind of joke to, in many ways, discredit the idea of the just city or at least to indicate its extreme implausibility.

目的是要用作戏谑，在很多方面，使人怀疑正义之城的概念,或至少是要指明其极难令人置信。

耶鲁公开课 - 政治哲学导论课程节选

So that's really - these are really difficult questions to answer.

所以这些问题,这些问题都是极难处理的

耶鲁公开课 - 生物医学工程探索课程节选