OK PROFESSOR: Valence electrons. OK, sometimes you're going to be asked to draw a molecular orbital diagram where you're asked to include all electrons, and sometimes it will specifically say only include valence electrons.

教授：价电子，有时候你画一幅分子轨道图,有时候要求你画出所有的电子，有时候特别要求,只包括价电子。

麻省理工公开课 - 化学原理课程节选

And homework, it varies between classes. Sometimes you only get one assignment,

家庭作业，也跟课程的不同而有所差异。
有时候你只有一个作业，

很好奇住宿生活 - SpeakingMax英语口语达人

So you can only hurt the one you can love but the one who always loves you sometimes has trouble showing you that they love you.

所以你只会被所爱的人伤害,但是一直爱你的人,有时不善于表达他们对你的爱意。

耶鲁公开课 - 心理学导论课程节选

Don't seem to impose, don't seek to impose your own high-minded innocence, sometimes called justice, your own high-minded innocence on the requirements of statecraft because it will only lead to ruin.

不要似乎去强加，不要试图去强加,把你高尚的纯真，有时候被称作正义，你自以为的高尚纯真强加到管理国家的,必要条件上去因为它只会导致毁灭。

耶鲁公开课 - 政治哲学导论课程节选

There are cells within your body that are always in the process of division and forming new cells, and sometimes this is for a tissue where cells only have a finite lifetime.

你体内的一些细胞,始终在不断分裂,并生成新的细胞,很多时候,是在一些细胞寿命有限的组织中

耶鲁公开课 - 生物医学工程探索课程节选

And you'd also have baths; that is, public places, sometimes where only men could go, or sometimes women could go, or sometimes they would be mixed in some places.

还有浴室;,这是公共场所，有时只有男子能去，有时女子能去，有时可以男女共用。

耶鲁公开课 - 新约课程节选