OK, then it says draw a single bond from each surrounding atom to the central atom, and subtract two valence electrons.

后将中心原子与其相邻原子之间,连上单键，然后减掉2个价电子。

麻省理工公开课 - 固态化学导论课程节选

and in terms of just like where we set, we set with the curricular resource center,

然后那里设立奖学金，我们和课程资源中心设立，

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In other words, I look at a structure and I say it has a center.

换句话说，我看着一个结构然后我说她有一个中心。

耶鲁公开课 - 文学理论导论课程节选

No, they grow up like the Athenian does, right smack in the middle of a plain, which is a good place for farming, with a great high acropolis available.

它们和雅典的扩展方式类似,在一个平原的中心扎根,因为那里适合农业生产,然后建起一座高大的卫城

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