A.1 B.1.5 C.2 D.2.5
A.0.1~0.2 B.0.2~0.3 C.0.3~0.4 D.0.4~0.5
A.車(chē)頂 B.車(chē)廂 C.車(chē)底 D.車(chē)鉤連接處