Mr.Obama said the United States and NATO agree that it is critically important to dismantle the al-Qaida network and work effectively with the Afghan government to ensure security in the country.

VOA: standard.2009.09.29

So you know, what the second law is doing, in other words, it's putting these restrictions on how well or how effectively we can convert heat into work in the case of the engine, or work into heat extracted in the case of a refrigerator.

你们知道，在热机中，热力学第二定律的作用，换句话说，就是给热量,转化为功的效率,施加限制,或在制冷剂中，对抽取热量,进行限制。

麻省理工公开课 - 热力学与动力学课程节选

"We have good partnerships among the countries within each agro-eco system so that through this twinning they can learn lessons from each other and work together effectively through time."

VOA: special.2010.02.08

Democrats and Republicans must still work together to ensure our troops have the resources they need to more effectively fight extremists in the Middle East and around the world,"

VOA: standard.2009.04.28

I am optimistic that we are going to be able to manage this effectively, but we still have more work to do, and I am glad I have got such a great team doing it,"

VOA: standard.2009.05.01