The answer is right, but y=2/3 is wrong. The trick is that y be

来源: jinjing 于 2010-11-19 08:28:03 [] [旧帖] [给我悄悄话] 阅读数 : (58 bytes)
回答: The writer is not qualified being my student. 由 jinjing 于 2010-11-18 12:40:18

I would be student again.Goodby.I'm really too old.

请您先登陆，再发跟帖！