验证了一下，答案是对的，你们怎么想出来的？

来源: 继往开来于 2009-12-02 08:21:22 [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.