A:x>3
B:x≤3且x≠0
C:x≤3
D:x<3且x≠0
-You look so worried, what’s wrong?
-More and more people like me begin to worry about the ______ pollution after the haze (雾霾) appeared in Beijing and some other cities in China.
哨____ ____ 枪____ ____
防____ ____ 削____ ____