小题1:                                                                      

小题2:                                                                      

小题3:                                                                      

小题4:                                                                      

小题5:                                                                      

影响汽车燃油经济性的主要因素有耗油率、行驶阻力和（）等。

A.小修频率

B.轮胎翻新率

C.机械传动效率

D.故障率