下列气体中约占空气总体积的1/5的是A．氮气B．氧气C．二氧化碳D．

下列气体中约占空气总体积的1/5的是

A．氮气

B．氧气

C．二氧化碳

D．稀有气体

答案

B解析:
略

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下列气体中约占空气总体积的1/5的是A．氮气B．氧气C．二氧化碳D．

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