Walking tops the list. A two thousand six report from the C.D.C.found that more than seventy-nine million Americans walk to stay physically fit.

VOA: special.2010.06.08

It's roughly the same size physically as those floppy disks and yet how many, how much, how many bytes fit on a typical hard drive today?

从物理大小上来说几乎相同,那么现在的硬盘的存储大小,一般有多少字节呢？

哈佛公开课 - 计算机科学课程节选