A.115 B.123 C.155 D.156
A.機(jī)車重聯(lián)時(shí) B.機(jī)車附掛時(shí) C.無(wú)火回送時(shí) D.后部補(bǔ)機(jī)時(shí)
A.15s B.30s C.60s D.120s