在清单3中，可以看到head返回了一个元素，tail返回了一列元素。

In Listing 3, you can see that head returns an element, and tail returns a list of elements.

youdao

第一列元素最外电子层内均有一个电子，第二列元素则含有两个电子，依此类推。

Elements in the first column all have one electron in their outermost shell. Those in the second column have two outer electrons, and so on.

youdao

该算法每步运算可生成一列元素而不是一个元素，因而减少了运算次数，加快了生成速度。

Its each operational step produces a string of elements instead of one element. Hence the algorithm reduces the time of operation, and accelerates the speed of generation.

youdao

So it might be something like that, a tiny little something that one would set down like a couple of elements.

所以创作的支点可能是类似这些的，很小很小的事情，作者会把它们列出来,就像一系列元素一样。

普林斯顿公开课 - 人性课程节选

All right. So it's 7 that are in chlorine, it's the same as fluorine or any of the others in that row or in that group rather.

好，氯有七个，跟氟或者在那一列,的其它元素一样。

麻省理工公开课 - 化学原理课程节选

If you take some from column one or two and you mix it with some from column eight and nine, bingo, you have reaction.

如果你从第一列或者第二列中选出一些元素,将其与第8列或者第9列的元素混合，好，就会发生化学反应。

麻省理工公开课 - 固态化学导论课程节选