Human has been using base and acid for thousands of years.

来源: career 于 2017-03-22 18:23:08 [] [旧帖] [给我悄悄话] 阅读数 : 0 (263 bytes)
回答: 那个化学品不是Process Control生产出来的 由 will222 于 2017-03-22 17:44:52

They are made by God--long before IT.

嘻嘻

 

 

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