Responding to the need for safe, clean and affordable lighting, Irvine-Halliday set to work on a solution.

VOA: standard.2009.12.13

So, if you can't immediately know, and you don't all have periodic tables in front of you, so that's fine, but if you have a periodic table in front of you, you need to be able to count valence electrons, so work on that if it doesn't come naturally to you in terms of figuring that out.

如果你不能马上想到，而且你手上没有周期表，那还好，但如果你面前有一张周期表，那你就得具备从中查出价电子个数的能力，如果你不能自然而然地想到,请在这方面多下点功夫。

麻省理工公开课 - 化学原理课程节选

So, it doesn't need to bind to a receptor on the surface of the cell in order to work because the molecule can actually enter the cell directly.

所以无需与细胞表面受体相结合来起效,因为这些分子能直接进入细胞

耶鲁公开课 - 生物医学工程探索课程节选

"We'll need to work together on issues that are in the national interest on which there is no need to compete or permanently bicker,".

VOA: standard.2009.04.25

So if you need the help of the notes it's in there but I would urge you to work through it on your own, and it's the following: let's start with the same path A, all right?

如果你需要帮助，可以去看讲义,但我还是希望你们自己去推导它,它是这样的，让我们从：,相同的路径A开始，好吗？

麻省理工公开课 - 热力学与动力学课程节选

We need to make sure that all Americans, not just the folks who happen to work on Wall Street, feel that we are digging ourselves out of the hole,"

VOA: standard.2009.12.05

We need to continue our work on an economic recovery.

VOA: standard.2009.11.09

"We have to improve health care in general for everyday need and everyday purposes and if it does not work on an everyday basis of course in a crisis or in a disaster it is not going to suddenly work better,".

VOA: standard.2009.10.14

"We need leaders who are committed to moving New Jersey forward, (Applause) and that is John Corzine, which is why you need to work hard on Tuesday!" A Republican sweep will be seen by some as a rejection of President Obama's policies and could embolden Republican efforts to win congressional seats in 2010.

VOA: standard.2009.11.02