前提：EFB和DFC必須是直線。

來源: SciTech 於 2018-09-28 07:44:31 [舊帖] [給我悄悄話] 本文已被閱讀：次

隻需證明：DE//BC

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

Change Ad Consent