关键点：载体线程永远不会因为虚拟线程的 IO 等待而阻塞，它们一直在执行不同的虚拟线程。一个载体线程可以在一秒钟内服务几十个虚拟线程（因为每个虚拟线程真正占用载体线程的时间很短，大部分时间在等待）。
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.
，推荐阅读体育直播获取更多信息
has(key: string) {，详情可参考体育直播
Insider says demand is far outstripping supply and calls for creation of air bridges to evacuate people from Middle East。体育直播对此有专业解读
During their first foundation year after finishing their medical degree, resident doctors in England earn a basic salary of £38,831. In their second year, this rises to £44,439.