Use
(1) Electricity Development: Dam, Drain, Canal, Sand Basin, Power Station, Reservoir.
(2) Bay & River: Breakwater, Retaining Wall, Caisson, Bank.
(3) Railway & Highway: MRT, High-speed Railway, Tunnel, Viaduct, Subway, Waterway, Cavern.
(4) Water Conservancy: Intake Gate, Reservoir, Drain, Bifurcation Gate, Open Ditch Irrigation.
(5) Mansion & Building: Basement, Pool.