"Many mothers deliver at home in sub-Saharan Africa and it's very difficult for them to get to a hospital or clinic which may be miles away in that time period.

VOA: special.2010.05.24

For some of you it may be difficult I know that and I want you to rest assured that no one in this course wishes to undermine or malign religious faith any more than they wish to promote or proselytize for religious faith.

我知道对你们中的另一些人来说这门课会有困难,不过我想要你们放心,这门课上没有人想要破灭和诋毁宗教信仰,同样也没人想要劝诱他人信教。

耶鲁公开课 - 旧约导论课程节选

Whatever else it may be, everyone's always agreed that modern poetry is difficult. You will probably too.

不管是什么，每个人都会赞成,现代诗歌是艰深的，你或许也会认同这点。

耶鲁公开课 - 现代诗歌课程节选

There may be circumstances under which it's the case but it's often difficult to control.

可能在某些环境下可以做到,但是通常情况下很难控制。

麻省理工公开课 - 热力学与动力学课程节选