______no friction between the surface of t
题型:单项选择题
问题:
______no friction between the surface of the road and our feet, we could not walk at all.
A.If there was
B.Were there
C.Was there
D.There was
______no friction between the surface of the road and our feet, we could not walk at all.
A.If there was
B.Were there
C.Was there
D.There was