下列气体既会造成酸雨，又可用作防腐剂的是（ ）。

试卷相关题目

SQL Error: select id,body,options from ***_enewstiku where sourceid='31028' and id < 2496536 and id<>'2496536' order by id desc limit 5 SQL Error: select id,body,options from ***_enewstiku where sourceid='31028' and id > 2496536 and id<>'2496536' order by id asc limit 5