Google page speed 性能优化
优化前：53分
https://developers.google.com/speed/pagespeed/insights/?url=http%3A%2F%2F173.199.126.118%3A8080%2Fsubject_list.htm&tab=desktop
优化后：95分
https://developers.google.com/speed/pagespeed/insights/?url=http%3A%2F%2F173.199.126.118%2Ftest%2Fsubject_list.htm&tab=desktop