好,您可能笔误,是r^2 不是v^2.

来源: jinjing 于 2011-01-18 13:11:44 [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.