This is very easy molecule because we know exactly where to put them without even having to think, we only have one option, and we'll make a triple bond between the carbon and the nitrogen.

这个分子非常简单,因为我们知道应该把它们放在哪里,甚至不用去想，我们只有一个选择，我们将在碳与氮之间形成一个三键。

麻省理工公开课 - 化学原理课程节选

What you can do is you can iterate keys, which gives you the keys in the dictionary, and then you can choose them, but there's no guarantee in the order in which you get keys.

你能做的就是迭代得到键，这样就可以得到字典中，所有的键并进行选择，但是键的顺序,是没有保证的。

麻省理工公开课 - 计算机科学及编程导论课程节选