Darwin's observations showed him that environments can change a little very quickly and a great deal over time.

VOA: special.2009.02.27

it's the study of how languages change over time.

它研究的是语言的历史变化。

我的专业 - SpeakingMax英语口语达人

Now,that has changed, for sure; but,the centralization of the French government and the domination of Paris over the life of the nation is very difficult to change, over a long period of time.

现在,情况已经发生了改变,但是法国政府的中央集权化,以及巴黎在国民生活中的支配地位,在相当时间段内,都很难得以改变

耶鲁公开课 - 1871年后的法国课程节选

Rosalyn Schanzer brings to life the clues that suggested to Darwin that living things evolve, or change,over time.

VOA: special.2009.02.27

And so, if you rewind the tape and play it again over and over and over again, each time you set things up the very same way they must move or transform or change or end up in the very same state.

所以,如果你将一盘磁带,反反复复地播放,每次你播放的内容,从头到尾的起承转合一定是,绝对一致的

耶鲁公开课 - 死亡课程节选

But they say the land formation continues to change slowly over time.

VOA: special.2009.04.15

Katrin Verclas says she hopes FAILFaire will change this problem over time.

VOA: special.2010.09.13

Some genes change or disappear over time.

VOA: special.2010.02.02

"Because it's happening so quickly, they haven't had time to adapt and change, if you imagine a climate changing over hundreds of thousands of years, bears and other animals would gradually move into other habitats,but because this is going to happen over decades, it will be too fast for them to adapt and look for other food sources,"

VOA: standard.2009.12.13