各种物质，不论它是什么，都是由一些称为分子的很小的粒子构成的。

Every substance, no matter what it is, is composed of very small particles called molecules.

《新英汉大辞典》

所以我们需要知道,就是各种物质的自由能。

So we need to know the free energy of each one of the species.

youdao

相反，她在班级里很活跃，对各种物质和如何利用它们都有很强的好奇心。

Instead she focuses on the classes, becoming curious about the material and how she can apply it to her interests.

youdao

People need fat, and they need sugar, and they need variety--at least what their brain thinks.

人类需要脂肪和糖类,需要各种物质,至少大脑是这么认为的

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选

in spite of the fact that we take a variety of chemicals into our bodies in different ways and we have to do that to stay alive, but we have mechanisms to control this very well.

尽管事实是我们从不同途径,摄入各种化学物质以维持生存,但我们能够很好地控制它们在体内的总量

耶鲁公开课 - 生物医学工程探索课程节选