有点纳闷，这图为啥用圆来表示，不能用方的或是三角形来表示？

来源: yy888 于 2011-09-29 11:25:08 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次

WENXUECITY.COM does not represent or guarantee the truthfulness, accuracy, or reliability of any of communications posted by other users.