在大海中航行,尽管波涛将你托起,浪花与你嬉戏,但你却不敢稍饮一点海水,即使你已渴得嗓子冒烟,嘴唇干裂。地球上97.5%的水正是这种目前人类还无法直接饮用的咸水。在仅占2.5%的淡水资源里,绝大多数的水是以冰的形态存在于南北极,而且主要以冰川和深层地下水的形式存在。与人类生活最密切的湖泊、河流和浅层地下的淡水,仅占淡水总 Sailing in the ocean, though the waves hold you up and the waves are playing with you, you dare not drink a little of the sea, even though you have thirsty throats and chapped lips. 97.5% of the earth’s water is the salt water that humans can not drink right now. In just 2.5% of freshwater resources, the vast majority of water is in the form of ice in the North and South Pole, and mainly in the form of glaciers and deep groundwater. The lakes, rivers and shallow groundwater, which are the closest to human life, account for only fresh water