曾国藩的前辈老乡、大儒王船山的话更厉害——比如，为储粮备荒、平抑物价、赈灾救急等等，历代由朝廷或地方乃至乡绅出资建义仓、社仓，这是不是慈善？当然是。可是王船山反复批评这种义仓、社仓。为什么？因为它的作用有限而流弊益多，且以公义之名，蔽人眼力、阻人思想。正如当今由单位机构出钱组织义务写春联、送春联，固然是善事，但这种公益活动的流弊实在太大，同样以公义之名，蔽人眼力、阻人思想、消解人参与体验。
The quadtree is the two-dimensional case of a broader family of space-partitioning data structures. Octrees extend the same idea to three dimensions (splitting cubes into eight children), KD-trees use alternating axis-aligned splits (splitting along x, then y, then x again), and R-trees group nearby objects into bounding rectangles. Each variant makes different tradeoffs between construction time, query speed, and update cost.
，这一点在快连下载安装中也有详细论述
Running pre scripts... done。业内人士推荐谷歌浏览器【最新下载地址】作为进阶阅读
many items are in c.)，更多细节参见同城约会