下面域名都是有效CDN域名,指向相同文件
assets.zhihuishu.com
assets-1.zhihuishu.com
assets-2.zhihuishu.com
assets-3.zhihuishu.com
assets-4.zhihuishu.com
assets-5.zhihuishu.com
assets-6.zhihuishu.com
assets-7.zhihuishu.com
assets-8.zhihuishu.com
assets-9.zhihuishu.com