电机车在运行过程中突然车体歪斜，左右摇晃是（）原因
A、机车断轴
B、缓冲弹簧折断
C、架线高度不够
D、运行路段坑洼不平
参考答案：A, B, D
—Where is your brother?
—He has gone to Beijing. He back in three days.
A．will come
B．comes
C．has come
D．came
悬挂犁耕宽调整的目的是为了减少漏耕和（）
