Overpumping groundwater for drinking water and irrigation has caused water levels to decline by tens of metres in many regions,forcing people to use low-quality water for drinking. 过度抽取地下水做为饮用水和用来灌溉在许多地区已经使水位下降了几十米，迫使人们使用质量较差的水来做为饮水。
When mining large databases, the data extraction problem and the interface between the database and data mining algorithm become become issues. 对大型数据库进行数据开采时，数据抽取问题及数据库和开采算法的接口设计就变得十分重要。
