A.1850±50mmB.1750±50mmC.1650±50mmD.1550±50mm
A.防護各進路的調(diào)車信號機同時開放B.防護各進路的調(diào)車信號機信號由遠及近開放C.防護各進路的調(diào)車信號機信號由近及遠開放D.哪條進路建立,防護進路的那架信號機就開放
A.30SB.60SC.120SD.180S