下列哪一项不是光化学烟雾的成分

A、PAN[img=~/QImg/2013-10-14-11-46-19/image008.jpg]
B、O[img=~/QImg/2013-10-14-11-46-19/image003.jpg]
C、醛类
D、H[img=~/QImg/2013-10-14-11-46-19/image002.jpg]SO[img=~/QImg/2013-10-14-11-46-19/image004.jpg]
E、HNO[img=~/QImg/2013-10-14-11-46-19/image003.jpg]