The substance of his discussions doesn't really matter.

他讨论的要旨实际并不重要。

《柯林斯英汉双解大词典》

Petrifaction may also involve a simultaneous exchange of the original substance of a dead plant or animal with mineral matter of a different composition.

石化还可能同时涉及将死亡的动植物的原有物质与不同成分的矿物质进行交换的作用。

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

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。

《新英汉大辞典》

The matter the substance the material basis of a regime concerns its citizen body.

本质，政体的物质基础,是其公民本体最关心的。

耶鲁公开课 - 政治哲学导论课程节选

If the very idea of soul that we're working with here under the dualist picture is the soul as an immaterial substance, it's not made of ordinary atomic matter.

如果关于我们正在讨论的,观点是建立在二元论的基础上,即灵魂是非物质实体,它并非由一般的原子物质组成

耶鲁公开课 - 死亡课程节选

How does this go to the substance of the matter, which is the recess appointment itself?

WHITEHOUSE: Press Briefing

There, finding just the right substance is a matter of painstaking trial and error, which has continued over decades.

ECONOMIST: Combinatorial chemistry

It could also cast light on the mystery of dark matter, a substance that pervades the universe in vastly larger quantities than familiar, visible matter, but whose existence can be inferred only by watching its gravitational effect on visible matter.

ECONOMIST: Particle accelerators