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【单选题】
空气是一种宝贵的自然资源。下列有关空气的说法不正确的是( )A.
氮气的化学性质不活泼，可用于食品的防腐
B.
燃烧法测定空气中氧气的含量，不能用硫代替红磷
C.
空气的成分按质量计算，氧气大约占21%
D.
禁止燃放烟花爆竹，可以减少空气污染
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