However, the thing to remember is, when you look at heats of reaction under those conditions it's all well and good.

相反，需要记住，当你需要知道反应中放出的热量时,这些量是很有用的。

麻省理工公开课 - 热力学与动力学课程节选

that it's not needed that you don't want whatever it is near you or around you

你不需要这些东西,甚至当它们出现在你身边时你也不想得到。

I don't care课堂 - SpeakingMax英语口语达人

But now, when you need more, you can't just say I only want the best bottom land there is.

然而当你需要更多土地时,你不能张口就要这片地区最富饶的土地

耶鲁公开课 - 古希腊历史简介课程节选

Anything where you're actually keeping track of something like a score that's having a variable that you increment -- plus, plus, or decrement, minus, minus, using the appropriate puzzle piece could certainly be compelling.

你需要保存像分数这样的事物时,你就需要一个变量,它可以自加，++，或者自减,要使用正确的拼图。

哈佛公开课 - 计算机科学课程节选

So wherever you happen to be, when you run out gas, there was a gas station close by.

这样无论你在哪里需要加油时,附近就会有一个加油站

耶鲁公开课 - 博弈论课程节选

It turns out that when you're talking about macroscopic properties of matter, you don't need very many variables to describe the system completely thermodynamically.

实际上,当你谈及物质的宏观性质时，你并不需要很多变量才能从热力学上,完整地描述这个系统，’

麻省理工公开课 - 热力学与动力学课程节选

This should make sense because if something has a low ionization energy, that means it's not very electronegative, which means it's going to be a lot happier giving up electron density, which is essentially what you're doing -- when you're forming covalent bonds is you're sharing some of your electron density.

这应该是合理的,因为如果某物的电离能很低，这也就意味着它的电负性也不高，那么它就会更愿意,放弃一定的电子密度，而本质上这正是你在,形成共价键时所需要做的,分享你的一些电子密度。

麻省理工公开课 - 化学原理课程节选

It is true mathematically, you can add two numbers, but you've got to ask yourself,"What am I doing as a physicist when I add these two numbers?"

在数学上它是正确的,你可以引入这两个常数,但是你需要问问自己,当我引入这两个常数时,这么做有什么物理意义

耶鲁公开课 - 基础物理课程节选

Because you see, also motivation and energy-- you don't need research for that, you know that when you are feeling good, you have more motivation, you have more energy-- of course, there is a lot of research to back that up.

因为动力和精力-,不需要研究就能明白，你知道感觉好时，动力和精力更充沛-,当然有很多研究支持这一点。

哈佛公开课 - 幸福课课程节选

You use "I can't help but" when you feel helpless, when you want to get something across that needs to happen.

当你觉得无助时，或者当你说明需要做到这件事情的时候，你就可以使用“I can't help but”句型。

I can't help but 课堂 - SpeakingMax英语口语达人

Speed, right. So another decision you face is do you just try and kick this ball as hard as you can or do you try and place it?

球速是正解,你还需要考虑,当你主罚点球时你是大力抽射,还是小力轻擦

耶鲁公开课 - 博弈论课程节选

Occasionally, you'll find you need to cancel out units, because, of course, you're always doing unit analysis as you solve your problems, and sometimes you'll need to convert joules to kilogram meters square per second squared.

偶然地，你会发现需要消除单位，因为在解题时,经常要做单位分析，所以有时候需要把,焦耳换做,一千克乘以米的平方除以秒的平方。

麻省理工公开课 - 化学原理课程节选

As you come to the top of the building, the elevator has to decelerate, so that it loses its positive velocity and comes to rest.

当你要到顶时,电梯需要减速,此时电梯速度减小最后静止

耶鲁公开课 - 基础物理课程节选

In the other context, you know in a Window and a Windows machine, you close it with the X on the top right hand corner, where do you close it in the Mac?

还有一个就是，在Windows操作系统下,当你要关闭某个东西时，需要点击,右上角的“X“,那在Mac操作系统下呢？

哈佛公开课 - 计算机科学课程节选

As an aside, if you ever just have one line of code that you want to execute, one puzzle piece in Scratch terminology, ; you actually don't need the curly braces; you only need the curly braces if you have two or more lines of code that you want to execute if that condition is true.

此外，如果你只有一行代码,需要执行，在Scratch，术语中叫做,一句代码，你就不需要使用花括号了;,如果那个条件成立，你有两行或更多行的代码时需要执行时,你就需要花括号。

哈佛公开课 - 计算机科学课程节选