A.供變電接觸網(wǎng)系統(tǒng) B.通信信號系統(tǒng) C.客運(yùn)服務(wù)系統(tǒng) D.軌道結(jié)構(gòu)
A.30mm,5mm B.50mm,2mm C.50mm,5mm D.25mm,5mm
A.6 B.8 C.10 D.12