已知中国境内家马的出现，大约晚至距今4000年的黄河上游地区，例如属于齐家文化的甘肃永靖大何庄遗址、玉门火烧沟遗址等。而黄河中下游地区出现家马，则更晚至商代晚期的安阳殷墟遗址。
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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.
Отмечается, что стоимость подобной операции в Москве колеблется от 600 тысяч до 1,2 миллиона рублей.