A.HY點處緩和曲線曲率半徑為R,外軌抬高為0 B.HY點處緩和曲線曲率半徑為∞,外軌抬高為ho C.HY點處緩和曲線曲率半徑為R,外軌抬高為ho D.HY點處緩和曲線曲率半徑為∞,外軌抬高為0
A.1:500 B.1:200 C.1:1000 D.1:2000
A.30km B.20km C.10km D.40km