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
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