In fact, the big airlines often save money by using smaller ones to carry passengers.

VOA: special.2009.06.13

That DNA gets replicated to make many more copies of the viral DNA using host mechanisms, that is, often using the DNA polymerase which is naturally present in the host cell for its own replication.

病毒DNA进行复制,通常是利用在宿主细胞自身的有关物质,利用宿主细胞中天然存在的,DNA聚合酶来大量复制病毒DNA

耶鲁公开课 - 生物医学工程探索课程节选

This is another wonderful pattern that you maybe are not now using often.

这个句型你可能之前并不常常使用，但它也是个非常棒的句型。

I'm frustrated 课堂 - SpeakingMax英语口语达人

As carefully as people work with radioactivity here, and using often much, much safer radioactive materials than radium bromide, and using them, and special hoods, and having special procedures, they still do a lot of checking with these Geiger counters to make sure everything's safe.

虽然在这里人们,用放射性物质都非常的小心，而且通常用的材料放射性,都比溴化镭要小得多，并且用的时候,都用特殊的容器,特殊的操作过程,但我们平时仍会用。

麻省理工公开课 - 化学原理课程节选

But when you start writing programs, especially when we get to web-based stuff where you want -- to check the user's input -- is it valid, is it an email address, -- and all these different scenarios -- it's actually often useful to be able to just enumerate them or rattle them off using this switching construct instead.

但是当你看是写程序时，特别是当我们,使用基于网络的东西，你想要,检查用户的输入-,它是合法的吗？它是不是一个电子邮箱地址？,所有的这些场景-,实际上它常常是有用的，当你用枚举结构列举它们,或者用它来快速地来说出它们。

哈佛公开课 - 计算机科学课程节选

This is so obvious in this problem, but when you see more complicated formula, you may not know all the assumptions that went into the derivation and quite often you will be using it when you shouldn't.

在这道题中这些都很明显,但是当我们用更复杂的公式时,你可能搞不清楚所有,在推导时的前提,因此很多时候,你都会用错公式

耶鲁公开课 - 基础物理课程节选

The "I want to" pattern is a great pattern that you probably have been using and you should use often.

I want to”句型是一个非常棒的句型，你可能之前早已用过，你也可以多多使用这个句型。

I want to 课堂 - SpeakingMax英语口语达人

So that means that we don't have to worry about things like wave functions when we're talking about Lewis structures, but because they're so simple to use and because they so often predict the electron configuration of molecules accurately, we end up using them all the time in chemistry, so it's very valuable to know how to draw them correctly and to know how to work with them.

因此这也就意味着我们在讨论路易斯结构的时候,不需要担心波函数之类的东西，但是由于路易斯结构不仅简单易用,而且用它来预测分子的电子排布,经常可以得到非常精确的结果，结果我们在化学中一直都在用它，因此知道如何正确地画出并运用,路易斯结构是非常有价值的。

麻省理工公开课 - 化学原理课程节选