When it does happen, when the idea comes and you wrestle to place the words that express exactly what it is that you want to say, what it is that the meaning you're wrestling for.

当其真的发生时,你绞尽脑汁,希望写出,能准确表达它的文字，你苦思冥想，究其含义。

普林斯顿公开课 - 人性课程节选

You will find this pattern very useful anytime you're not feeling happy about something and you want to express yourself.

你会发现，当你因为什么事感到低落，你想表达自己的感觉时，这个句型特别有用。

I get so upset 课堂 - SpeakingMax英语口语达人

For now, just know that different kinds of cells, one of the ways they're different is that they express different proteins and the population of proteins on the surface of different cells is different.

现在,你们只要知道有不同的细胞,它们之间的一种区别,就是它们表达不同的蛋白,而不同细胞表面的蛋白种类,也是不同的

耶鲁公开课 - 生物医学工程探索课程节选

And it's a useful pattern when you want to express that your feelings have been hurt or that you're not liking something,

当你想表达你在情感上受到了伤害或者不喜欢某件事的时候，这是个很有用的句型。

I get so upset 课堂 - SpeakingMax英语口语达人

And you would express this pattern if you're concerned about something that's about to happen,

当你对可能发生的事有所担忧时，你可以用这个句型来表达。

I'm worried 课堂 - SpeakingMax英语口语达人

The second issue is that the gene vector, in this case the plasmid, has to be compatible with the cells that you're trying to express the gene in.

接下来的问题是如何选择合适的基因载体,在这里用到的,质粒,必须与要用来表达基因的,受体细胞匹配

耶鲁公开课 - 生物医学工程探索课程节选