社会的基本单位是家庭。

The basic unit of society is the family.

《牛津词典》

单词是语言结构的基本单位。

Single words are the building blocks of language.

《牛津词典》

它和千克（10升蒸馏水的重量）一起构成了公制计量的基本单位。

Together with the kilogram, initially the mass of a decaliter of distilled water, it formed the basis of the metric system.

youdao

By the way, in what I'm saying, I oversimplify by supposing that the basic unit of language is a word.

因为我想说的是，我们现在是把语言的基本单位简单化了。

耶鲁公开课 - 文学理论导论课程节选

We talk about cells as being kind of the fundamental unit of humans and other multi-cellular organisms.

我们某种意义上把细胞视为,人体和其它多细胞生物的基本单位

耶鲁公开课 - 生物医学工程探索课程节选

But depending on the unit chosen, the associational networks will differ.

选择不同的基本单位，这种联系也大相径庭。

耶鲁公开课 - 文学理论导论课程节选