有點納悶，這圖為啥用圓來表示，不能用方的或是三角形來表示？

來源: yy888 於 2011-09-29 11:25:08 [博客] [舊帖] [給我悄悄話] 本文已被閱讀：次

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