倆字說的是倆不同的D，挺是剛度，粗是圍度，這裏用粗是強調圍度

來源: 才迷於 2016-12-22 07:51:02 [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.