There are so many foggy days recently.We all wonder_________.( )
A.how is the air polluted
B.why the air is seriously polluted
C.what can we do to prevent that bad weather
D.what are the real reasons
There are so many foggy days recently.We all wonder_________.( )
A.how is the air polluted
B.why the air is seriously polluted
C.what can we do to prevent that bad weather
D.what are the real reasons