发生光化学烟雾事件的主要污染物是（）。
A.SO2和颗粒物
B.SO2和NOx
C.颗粒物和烃类
D.烃类和NOx
E.烃类和SO2
参考答案：D
---It cost me 30 yuan to get here.
---Well, it was crazy of you to take a taxi you would come by bus as well.
A．unless
B．when
C．if
D．because
※ [43～44] ( ) . ( 5 )
