遇到问题时参考网址
https://blog.csdn.net/shark_tear/article/details/39523667
http://blog.sina.com.cn/s/blog_757fc71d0102w7bb.html
https://blog.xgheaven.com/2018/10/14/the-trouble-of-installing-centos7/
https://www.xiaoweigod.com/pc/1337.html
https://www.codenong.com/cs106872330/
https://blog.csdn.net/qq_44714603/article/details/88829423