There is Bohr at the center, and there is Heisenberg who is the one electron orbiting the center.

波尔在中间，这儿是海森堡,就像一个电子围绕着中心运转。

麻省理工公开课 - 固态化学导论课程节选

then what you have is a carbon in the middle with three hydrogens around it, and then it can only be bonded to one other thing.

那么你就会有一个碳原子在中心,三个氢原子围绕着它，那么它只能再和一个原子成键。

麻省理工公开课 - 化学原理课程节选