Milton claims that he will one day use the English language to express what he calls "some graver subject," some more important subject matter, and he proceeds to characterize what that graver subject will look like.

弥尔顿声称有一天他将用英语,来表达他所谓的“一些严肃的主题“,还有一些更重要的主题，然后他继续描述这些严肃的主题都是什么样的。

耶鲁公开课 - 弥尔顿课程节选

And try and use them that day, several times.

然后试着在那天把它们用上几次。

有这样的困难 - SpeakingMax英语口语达人

And you'll use each of those smiles at different points in your day and in your life.

你可以用其中的任意一种,在你生活的不同日子，不同情形下。

耶鲁公开课 - 心理学导论课程节选