Subsidence once provided a use for the China Steel Corporation's blast furnace slag, which was used as landfill in sunken areas, but the cost was horrendous, and it tied up large numbers of men and vehicles.
地層下陷，一度讓中鋼的廢棄爐渣有用武之地，拿來填補下陷地，但成本驚人，也填得人疲車困。