Over time,genes develop changes, known as mutations.

VOA: special.2010.02.02

In that case, we understand it as a sequence of cross-sections rather than something that somehow organically changes through time.

这样，我们就是在学习一个个语言的横截面,而不是语言自然的变化过程。

耶鲁公开课 - 文学理论导论课程节选

Your mortgage payment is constant through time but the fraction of it that goes to paying off principal versus interest changes through time and it just changes as dictated by this formula.

抵押贷款每月还款是固定的,但是其中本金和利息的比例关系,会随时间而改变,这是由这个公式所决定的

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