The air in mountain areas is ____ that i
题型:选择题
问题:
The air in mountain areas is ____ that in big cities.
A.as fresh as
B.fresher than
C.as dirty as
D.dirtier than
The air in mountain areas is ____ that in big cities.
A.as fresh as
B.fresher than
C.as dirty as
D.dirtier than