单项选择题
A.小于等于280KM/HB.小于等于240KM/HC.小于等于220KM/HD.小于等于160KM/H
A.880kPaB.1200KPaC.1100KPaD.1000KPa
A.动车组司机B.保洁人员C.车长D.乘务员