You have discribed the border as a safe where things the Taliban just go over there, when they are chased by the Afghan troops and Nato and then they come back then things are a little bit cooler.

您把这个边境线描写成一个关卡,当塔利班分子被阿富汗和北约军队追击时，他们就越过边界线,风声不紧时，他们又通过这个关卡回来。

普林斯顿公开课 - 国际座谈会课程节选

b OK. In this example I'd use b. All right, as b get-- b is the thing that's changing as I go along here, but it could be things like, how many elements are there in a list if the input is a list, could be how many digits are there in a string if the input's a string, it could be the size of the integer as we go along. All right.?

好，在这个例子里我会用，因为b是一直在变的东西,但是也可能是如下情况：,如果输入是数组的话,变化的就是数组的元素数，如果输入是字符串的话,变化的就是字符串的长度，如果是integer的话,可能就是这个数的大小，对不对？

麻省理工公开课 - 计算机科学及编程导论课程节选