That's just the simple sequential sense of "first," the first that comes before second, third and fourth; but there's something more radical here than the ordinal or sequential sense of "first."

这只是“先“表示顺序的简单含义,先于第二，第三，第四的那个“先“，但这里,“先“除了表示顺序的意思外还有更激进的含义“

耶鲁公开课 - 弥尔顿课程节选

0 And we'll also see backslash 0 which is actually the special character that's used at the end of a string to say no more string after this point in memory.

还有0,用于存储器中字符串末尾,表示在此之后就,没有字符了。

哈佛公开课 - 计算机科学课程节选

The other thing is that we can re-write our h c n in terms of bonds.

还有一件事是我们可以用键的形式来表示氰化氢。

麻省理工公开课 - 化学原理课程节选

There is another orthography that is used to indicate dipole.

表示偶极还有一种方法,表示偶极。

麻省理工公开课 - 固态化学导论课程节选

So this is a little bit trickier to look at and see what it means, but essentially we have two hybrid orbitals, which are shown in blue here, and then we have one p orbital that's left alone that's going up and down on the page.

看这个图肯能会觉得比较诡异，但本质上，骂我们有两个杂化轨道，这里用蓝色表示，还有剩下一个p轨道,在图中上下方向上。

麻省理工公开课 - 化学原理课程节选