The efficiency depends on the query size relative to the data distribution. A small query in a sparse region prunes almost everything. A query that covers the whole space prunes nothing (because every node overlaps), degenerating to a brute-force scan. The quadtree gives you the most benefit when your queries are spatially local, which is exactly the common case for map applications, game physics, and spatial databases.
million dollars and more often above that point than below. They were also large
，详情可参考WPS官方版本下载
英國商會（BCC）估計，15%的關稅稅率上調將使英國出口到美國的商品關稅成本增加20億至30億英鎊（27億至40億美元）。
Easy to understand reports