问题
选择题
There are so many foggy days these days. We all wonder .
A. how is the air polluted
B. why the air is polluted seriously
C. what are the real reasons
答案
答案：B
题目分析：句意：---这些日子有许多雾天。我们都想知道为什么空气被污染的这么严重。根据句子意思，故选B.