房屋的钥匙是从一个环上卸下来的。

The house keys are peeled from a ring.

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在底部，点，有一个环。

P So here at the bottom, at this point P, there is a loop.

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如果其中任何一个环被拆除，它们才都会来分开。

If any ring were removed, they would all come apart.

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Milton had written in Areopagitica that he had actually met Galileo on his journey, when Milton was a young man and Galileo was a very old man, through the continent.

弥尔顿在中已经写到,他实际上在旅途中曾经遇到过伽利略，那还是当他是一个年轻人，而伽利略已然老去的，一次环陆旅行中。

耶鲁公开课 - 弥尔顿课程节选

Benzene is a ring that's made up of six carbon atoms and six hydrogen atoms.

苯环是一个由六个碳原子,和六个氢原子组成的环。

麻省理工公开课 - 化学原理课程节选

And orbiting around this is a lone electron out at some distance r.

有一个单电子,在环原子核的轨道上运行。

麻省理工公开课 - 固态化学导论课程节选