如果我沒記錯的話，初中生物課教材中就講過這個問題了。

來源: pta 於 2014-06-22 13:21:51 [博客] [舊帖] [給我悄悄話] 本文已被閱讀：次

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如果我沒記錯的話， 初中生物課教材中就講過這個問題了。