Track circuits detect__1__if a train is occupying a block.
举一反三
- block signal A: a fixed signal that lets engineers know if a train can enter a block. B: a conductive connector used to maintain circuit continuity for track circuits and electrified tracks.
- manual block A: block controlled manually by a person known as a block operator. B: a fixed signal that lets engineers know if a train can enter a block.
- a fixed signal that lets engineers know if a train can enter a block. A: ABS (automatic block system) B: lock C: lock signal
- A _______ line is a track used exclusively for a high-speed train. A: train B: track C: welded D: dedicated
- A rate is a ______. A: speed B: train C: fast D: track