Most American colleges and universities use the grading system of A,B,C,D and F.

VOA: special.2009.03.05

Again I should have said first, index 0, the first one. I can similarly go in and say I'd like all the things between index 2 and index 4. And again, remember what a b c that does. Index 2 says start a 0. 1, 2. So a, b, c.

我还是要说一遍，索引为0的元素，是第一个元素，我可以要求返回索引,2和4之前的所有元素，请记住2,是从0开始的,那么0，1，2对应的是。

麻省理工公开课 - 计算机科学及编程导论课程节选

They are known as vitamins A, the B group,C,D,E and K.

VOA: special.2009.04.21