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

來源: jinjing 於 2010-11-19 08:28:03 [] [舊帖] [給我悄悄話] 閱讀數 : (58 bytes)
回答: The writer is not qualified being my student. 由 jinjing 於 2010-11-18 12:40:18

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

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