Surface water, such as river or lake, and urban sewage are cooling and heating resources of heat pump systems, which are considerable and spectacular in amount.

江河、湖泊等地表水和城市污水是两类数量巨大、极引人注目的水源热泵冷热源。

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Scientists are keen to study Antarctica's subglacial hydrological systems because liquid water beneath the ice sheet will influence its movement (the ice above Lake Whillans is moving at about 300m per year).

BBC: Drill reaches Antarctica's under-ice Lake Whillans