You notice at the beginning one-two, At the beginning these chords are holding for four measures or a total of eight beats.

注意在开头，在开始的部分，和弦持续了4小节也就是8拍。

耶鲁公开课 - 聆听音乐课程节选

This means we need a total of eight electrons in our molecular orbitals.

这意味着分子轨道里,一共有八个点子。

麻省理工公开课 - 化学原理课程节选