这里有一篇介绍一些背景资料，有兴趣的可以读一下。

来源: viewfinder 于 2013-01-06 09:35:28 [博客] [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.