下载APP
参考答案：
参考解析：
刷刷题刷刷变学霸
举一反三
【单选题】集中联锁车站的牵出线、机待线、出库线、专用线或其他用途的尽头线入口处的调车信号机前方,应设轨道电路,其长度不得小于( )米。
A.
45
B.
35
C.
25
D.
15
【单选题】Subways are underground trains, which usually operate 24 hours a day. They are found in larger cities and usually run between the suburbs and the downtown area. Maps and schedules are available from t...
A.
within downtown areas
B.
away from city centers
C.
in or outside big modern cities
D.
between suburbs and city centers