这一段结合了一点古代遗传理论，一点生物学知识。

This one ties in a little bit of ancient genetic theory, a little biology.

youdao

饭菜的流行时刻变化，但对营养学的基本概念应该保持很长一段时间，甚至是一辈子的事情。

Food fads come and go, but nutrition common sense can last a long, long lifetime.

youdao

你认为学英语的最佳年龄段是什么时候？

What do you think is the best age to learn English?

youdao

我学微积分已经有一段时间了。

It's been awhile since I did calculus.

youdao

我学英语有一段时间了。

I have been learning English for some time.

youdao

请听一段植物学课上的演讲。

Listen to part of a talk in a botany class.

youdao

请听一段植物学课上的演讲。

Listen to part of a talk in a botany class.

youdao