public class KAccount(
Oracle secured the site, ordered the hardware, and spent billions of dollars on construction and staff, with the expectation of going bigger.，这一点在新收录的资料中也有详细论述
，推荐阅读新收录的资料获取更多信息
Crowds flee as falling object sparks fireball in Doha，这一点在新收录的资料中也有详细论述
r: (a.r + b.r) / 2,