He says they are facing increasing restrictions on their ability to hunt or fish in their traditional homelands.

VOA: standard.2009.03.22

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

Although he called the U.S. decision to lift restrictions on Cuban-Americans to visit or send money to relatives in Cuba a "positive step,"

VOA: standard.2009.09.29

In an effort to battle Russia's rampant alcoholism, Russian President Dmitry Medvedev announced restrictions barring the sale of beer in cans or bottles larger than one-third of a liter.

VOA: standard.2009.10.15