We can never expect bluer sky unless we
题型:选择题
问题:
We can never expect bluer sky unless we create less polluted world.
A.a; a
B.a; the
C.the; a
D.the; the
We can never expect bluer sky unless we create less polluted world.
A.a; a
B.a; the
C.the; a
D.the; the