Some scientists now believe that tension headaches may result from changes among brain chemicals such as serotonin.

VOA: special.2010.03.30

In fact, temperature is such a carefully controlled parameter that when it changes just a little bit by a couple of degrees, we know that something's wrong.

事实上,体温被控制得如此精细,哪怕只改变几度,我们就能感觉出来不对劲

耶鲁公开课 - 生物医学工程探索课程节选

That - irreversible changes happen all the time too but here I'm talking about very subtle small changes where you're changing the structure of the protein but only a little bit such that it can go back.

这种不可逆的改变时时刻刻都在发生,但我在这里想讲的是,对蛋白质结构进行微小的改变,小到这种改变是可逆的

耶鲁公开课 - 生物医学工程探索课程节选

Some researchers and editors say changes must be made to stop such false author claims.

VOA: special.2009.10.08

They say such changes are events that have always happened.

VOA: special.2010.01.19

But in the end, protests and peaceful revolutions, such as in Poland,and changes in Moscow brought it down.

VOA: standard.2009.11.09

But Blatter and many in the football governing hierarchy have opposed such changes, saying they halt the free-flowing movement of the game and do not eliminate all mistakes.

VOA: standard.2010.06.29

A Royal Society research team member, Jules Pretty, says the team took into account a number of changes that are expected in coming decades, such as climate change, massive rises in world population, and new consumption patterns.

VOA: standard.2009.10.21