OK, so if we think of this function, u, that measures concentration, that means we are always going to go in the direction where the concentration decreases the fastest.

如果我们考虑函数u，它度量了浓度，也意味着，流动的方向，总是浓度减小最快的地方。

youdao

And having a chance to meet with all of you I think has given me great hope for the future of U. s. -china relations.

有机会和大家见面，使我感到美中关系的未来是很有希望的。

youdao

Carlos Santana told me that to think of yourself as a citizen of the U. S. is narrow. You have to think of yourself as a citizen of the world. You should be global.

Carlos Santana对我说别只把自己看成是美国的公民，这挺狭隘，要把你看成世界的公民，你应该是全球的。

youdao

Now,a team of U.S.scientists think they're on track to developing a "universal" vaccine that will protect people against all kinds of influenza.

VOA: standard.2010.07.21

"I think it is very important that the U.S.taxpayer not subsidize a project which will help Ahmadinejad out of his gasoline shortage problem,"

VOA: standard.2009.06.23

"I think that affected the Pakistani sentiment in terms of how it looked at the U.S.."

VOA: standard.2010.07.08

Many investors think of U.S. government bonds when they think of going on the defensive.

WSJ: As Many Stocks and Bonds Get Pricey, It's Time to Play Defense

What should the Japanese citizens within -- or between the 20 and 50 miles, what should they think of the U.S. recommendation?

WHITEHOUSE: Press Briefing

The poll indicates that about two-thirds of Americans think U.S. oil companies and foreign countries that produce oil are major causes of higher gas prices.

CNN: Poll: Country's mood at historic low