单选题

二氧化硫是我国当前大气中分布较广、影响也较大的主要污染物之一,时常以它作为大气污染的主要指标。在《环境空气质量标准》中,其一级、二级、三级的日平均标准分别为()。

A0.05mg/m3,0.15mg/m3,0.25mg/m3

B0.02mg/m3,0.06mg/m3,0.10mg/m3

C0.15mg/m3,0.50mg/m3,0.70mg/m3

D0.06mg/m3,0.15mg/m3,0.50mg/m3

正确答案

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