You've got vehicles, but you also have things like the tracks and the overhead wires and the tunnels themselves that need to be checked up on a regular basis.

- 你有车辆，但你也有轨道、架空电线和隧道本身需要定期检查的东西。

Pointlessly, ridiculously, they rose and walked about the table; seen thus, all that they did appeared incongruous—it was as though they were being jiggled carelessly and to no purpose by invisible overhead wires.

他们毫无意义地、可笑地站起来绕着桌子走来走去；这样看来，它们所做的一切都显得不协调——就好像它们被无形的架空电线漫不经心地摇晃着，毫无意义。