He says the current interest in straw bale houses is a direct response to the problem of climate change.

VOA: special.2009.10.05

I want to show you how easy it is to change the code. But, notice, once I've added this I actually have a problem. This is now an under-constrained problem. I have more unknowns than I have equations.

我加上这个条件后,我马上面临一个问题了,这就是现在是一个非约束性问题了,我的未知数比方程数多,你从代数中可以知道。

麻省理工公开课 - 计算机科学及编程导论课程节选

Change of--some small percentages, from eating? Not a problem.

一些微小的变化，比如吃饭？，没问题。

耶鲁公开课 - 死亡课程节选

So,we need to strengthen that foundation." The WMO chief says climate change is a global problem.

VOA: standard.2009.08.30

Delegates here say climate change is a global problem and can only be solved globally.

VOA: standard.2009.08.31

But Sow says it's difficult to get adults to change, for example, to stop using pesticides on their tomatoes and other crops, which he says is a persistent problem in the village.

VOA: standard.2010.04.01

And,there is a serious problem when you use the term 'regime change' that you might encourage people to demonstrate,or to act in ways, where we can do absolutely nothing to protect or encourage them."

VOA: standard.2010.06.11