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

A lot of the features you yourself use in Facebook these days are very much dynamic.

许多你在Facebook中使用的,特征功能都是极具动态的。

哈佛公开课 - 计算机科学课程节选