A.制動(dòng)缸壓力升壓至70kPa B.列車管壓力減壓70kPa C.按壓[警惕]鍵應(yīng)答 D.以上都可以
A.4s B.7s C.10s D.30s
A.10m B.20m C.30m D.50m