Classes can be composed of classes which themselves have parts, allowing you to hierarchically decompose a system to any arbitrary level.

类可以由那些拥有部件的类组成，允许您按照层级结构将一个系统逐步分解成任意的层次。

youdao

All matter is composed of tiny particles called atoms, which are themselves composed of smaller particles, electrons, neutrons and protons.

所有的物质都是由称之为原子的微粒组成，而原子本身则由更小的微粒，电子、中子和质子所组成。

youdao

Those molecules themselves are composed of smaller particles that have positive and negative charges of electricity.

那些分子本身是由若干更小的带有正负电荷的微粒所组成的。

youdao

United composed themselves and Paul Dixon's whipped cross found David Robertson, whose downward header was claimed by Rangers goalkeeper Neil Alexander.

BBC: Dundee United 0-3 Rangers

The All-Party Hurriyat Conference, composed of some two dozen separatist groups that are themselves divided over the role of the gun and over whether Kashmir should be independent or part of Pakistan, had prevaricated during the last peace move.

ECONOMIST: Kashmir

Currently it is composed of appointed life peers, senior bishops and 92 remaining hereditary peers who vote among themselves for who should join them when one of their number dies.

BBC: House of Lords Reform Bill