A.信號(hào)開(kāi)放 B.信號(hào)關(guān)閉 C.限時(shí)鎖閉 D.限時(shí)解鎖
A.30mm B.32mm C.34mm D.36mm
A.最低處 B.中間處 C.最高處 D.峰頂減速坡