（二）乏燃料，是指在反应堆堆芯内受过辐照并从堆芯永久卸出的核燃料。
Games and physics simulations need to detect which objects are touching or overlapping. With nnn objects, checking every pair is O(n2)O(n^2)O(n2) comparisons, which gets expensive fast. A hundred objects means roughly 5,000 pair checks. A thousand means nearly 500,000.
，更多细节参见91视频
self._init_table()。旺商聊官方下载是该领域的重要参考
accounts, since they need to be able to reconcile where their cash went. And，详情可参考搜狗输入法下载