CentOS 7 yum 不能安装package

CentOS7 使用yum安装时出现下面的错误：

[root@localhost Downloads]# yum install ncurses-devel
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
 * base: ftp.sjtu.edu.cn
 * extras: ftp.sjtu.edu.cn
 * updates: centos.ustc.edu.cn
http://mirror.lzu.edu.cn/centos/7.5.1804/os/x86_64/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found
Trying other mirror.
To address this issue please refer to the below wiki article 

https://wiki.centos.org/yum-errors

If above article doesn't help to resolve this issue please use https://bugs.centos.org/.

http://mirrors.zju.edu.cn/centos/7.5.1804/os/x86_64/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found
Trying other mirror.
http://mirrors.cn99.com/centos/7.5.1804/os/x86_64/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found
Trying other mirror.
http://ftp.sjtu.edu.cn/centos/7.5.1804/os/x86_64/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found
Trying other mirror.
http://mirrors.tuna.tsinghua.edu.cn/centos/7.5.1804/os/x86_64/repodata/repomd.xml: [Errno 14] HTTP Error 404 - Not Found
Trying other mirror.

使用以下步骤可以重新生成yum源：

yum-config-manager --save --setopt=base.skip_if_unavailable=true
yum makecache