• 2022-06-07 问题

    A _________________has a wider foot and narrower head. A: flat bottom rail B: ullhead rail

    A _________________has a wider foot and narrower head. A: flat bottom rail B: ullhead rail

  • 2022-06-15 问题

    ______is a device attached to a rail to prevent it from creeping in the direction of train travel. A: flat bottom rail B: ullhead rail C: ail ancho D: aseplate

    ______is a device attached to a rail to prevent it from creeping in the direction of train travel. A: flat bottom rail B: ullhead rail C: ail ancho D: aseplate

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