普速铁路线路修理规则单项选择题每日一练(2019.11.30)

A.2
B.4
C.6
D.8

A.1
B.2
C.3
D.4

A.1391mm
B.1390mm
C.1389mm
D.1388mm

A.0.1
B.0.2
C.0.3
D.0.4

A.15
B.20
C.25
D.30