重型轨道车由于机械故障不能继续运行,或由于其他原因在区间被迫停车时,司机应迅速鸣示()声的报警信号。
A、一长三短
B、一长两短
C、二短一长
D、连续短声
参考答案:A
What the boy ____ make his friends happy.
A.does did
B.did did
C.do do
D.do does
营养教育