DBSCAN算法基于密度的聚类的概念，即要求聚类空间中的一定区域所包含对象的数目不大于某一给定的阈值。-找考题网

单项选择题__________ There are more households living in actual poverty than there are households below the poverty line. A recent report states that as much as 30% of Americans have trouble making ends meet and other advocates have made supporting claims that the rate of actual poverty in the US is far higher than that calculated by using the poverty line. While the poverty line is updated for inflation every year, the basket of goods used to determine what constitutes being deprived of a socially acceptable minimum standard of living has not been updated since 1955.