One of the things about these plasmids that makes them very useful is that their entire base pair sequences is known.

质粒之所以有用,其中一个原因就是,它的全部碱基序列都是已知的

耶鲁公开课 - 生物医学工程探索课程节选

It depends on" is very useful when you're trying to make a decision when things are unclear and you're waiting.

当你在形势不明朗，仍在观望而无法做决定的时候，"It depends on"句型是一个非常有用的句型。

It depends on 课堂 - SpeakingMax英语口语达人

There are all kinds of things that it might be very useful ; for you to know as an inhabitant of Western civilization; and the New Testament,you might find out, would rank kind of down on the list of those kinds of things.

作为西方文明的一分子,有很多有用的东西可以学;,而新约，你会发现，与这些东西相比，排名比较靠后。

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That's very useful for things like chemical reactions where this constituent changes to this one.

对于化学反应之类的过程,这是非常重要的。

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