Old people don't like to vary their habits.

老年人不喜欢改变他们。

The epigenome is a molecular marking system that controls gene expression without altering the DNA sequence.

Image credit: Dreamstime表观基因是在不改变DNA序列前提下控制基因表达分子标记系。

Constituents that can be substituted for one another without loss of grammaticality belong to the same syntactic category.

可相互替换而又不改变语法属性成分属于同一句法类型。