（）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
A: If there was
B: Were there
C: Was there
D: There was
举一反三
- Without the friction between our feet and the ground, we (not, be) () able to walk.
- But for friction, people _________ neither walk, nor even stand up. A: can B: were able C: will be able D: could
- Were it not for friction, we ( ) walk on this earth of ours. A: should not have been able to B: would not be able to C: were not able to D: are not able to
- Were it not for friction (摩擦力), we ______walk on this earth of ours. ( ). A: were not able to B: should not have been able to C: would not be able to D: are not able to
- Without the friction between their feet and the ground, people would never be able to walk. A: in no time B: by all means C: in no way D: on any account