So if we want to put that in chemical terms, we want to make sure we put these in brackets here, and remember, this is the resonance arrow, it's not a reaction arrow, it's a resonance arrow, so make sure you mark it up correctly like that.

那么如果我们把它类比到化学中来，我们要确保它们都放在括号里，而且要记住，这是一个表示共振态的箭头，而不是表示化学反应的，它是一个表示共振态的箭头，因此请务必像这样正确地标记它。

麻省理工公开课 - 化学原理课程节选

In fact, he broke the 4 minutes and 10 seconds mark, 4 minutes and 5 seconds mark and he got 4 minutes and 2 seconds and stopped, like everyone else-- could not go below the 4 minutes and 2 seconds.

他突破了四分十秒，四分五秒,跑到四分两秒时停止，像所有人一样-,无法低于四分二秒。

哈佛公开课 - 幸福课课程节选