画图和标记箭头。

Draw pictures and make arrows.

youdao

画图和标记箭头。

Watch for digressions and mark them.

youdao

微小的箭头类似于战术地图上的方向标记，是他的军事世界中罕见的遗留物之一。

The faint arrows, similar to the directional markings on a tactical map, are one of the rare carry-overs from his military world.

youdao

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