By "difficult," it is meant, I think, well, first of all that it is in some sense set apart from common speech, as a specialized and highly self-conscious use of language.

艰深“的意思，我认为，首先，某种程度上它是和平时谈话有所不同的，专业性极强，对语言运用自知也很高。

耶鲁公开课 - 现代诗歌课程节选

Anybody whose read a basic finance text, as a matter of fact, I think anybody who thinks about investments in a common sense fashion knows that diversification is an important fundamental tenet of portfolio management.

事实上,任何一个读过金融基础教材的人,任何一个,以正常思维来考虑投资问题的人,都知道分散投资是投资管理的,一条重要的基本原则

耶鲁公开课 - 金融市场课程节选