在hosts文件最后一行添加：【友情提示：hosts所在目录C:WindowsSystem32driversetc】
直接选中以下内容复制粘贴，20210119有效（包括MAC系统）20210123更新
# GitHub Start
140.82.113.3 github.com
140.82.114.20 gist.github.com
151.101.184.133 assets-cdn.github.com
151.101.184.133 raw.githubusercontent.com
199.232.28.133 raw.githubusercontent.com
151.101.184.133 gist.githubusercontent.com
151.101.184.133 cloud.githubusercontent.com
151.101.184.133 camo.githubusercontent.com
199.232.96.133 avatars.githubusercontent.com
151.101.184.133 avatars0.githubusercontent.com
199.232.68.133 avatars0.githubusercontent.com
199.232.28.133 avatars0.githubusercontent.com
199.232.28.133 avatars1.githubusercontent.com
151.101.184.133 avatars1.githubusercontent.com
151.101.108.133 avatars1.githubusercontent.com
151.101.184.133 avatars2.githubusercontent.com
199.232.28.133 avatars2.githubusercontent.com
151.101.184.133 avatars3.githubusercontent.com
199.232.68.133 avatars3.githubusercontent.com
151.101.184.133 avatars4.githubusercontent.com
199.232.68.133 avatars4.githubusercontent.com
151.101.184.133 avatars5.githubusercontent.com
199.232.68.133 avatars5.githubusercontent.com
151.101.184.133 avatars6.githubusercontent.com
199.232.68.133 avatars6.githubusercontent.com
151.101.184.133 avatars7.githubusercontent.com
199.232.68.133 avatars7.githubusercontent.com
151.101.184.133 avatars8.githubusercontent.com
199.232.68.133 avatars8.githubusercontent.com
199.232.96.133 avatars9.githubusercontent.com
# GitHub End
然后保存文件就OK了，至于无法保存，没有修改权限，鼠标右键-属性-安全-修改权限；或将hosts文件复制一份，修改之后，复制到原文件夹替换！