执行yum -y install wget时，终端报错   

[root@localhost /]# yum install wgetLoaded plugins: fastestmirrorLoading mirror speeds from cached hostfileThere are no enabled repos. 

Run yum repolist all to see the repos you have. 

To enable Red Hat Subscription Management repositories: subscription-manager repos --enable <repo> 

To enable custom repositories:     yum-config-manager --enable <repo>

解决办法   

在终端运行以下内容后即可正常安装wget：

curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo

[root@localhost /]# curl -o /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo  

% Total    % Received % Xferd  Average Speed   Time    Time     Time  Current Dload  

Upload   Total   Spent    Left  Speed100  2523  100  2523    0     0   169k      0 --:--:-- --:--:-- --:--:--  175k

原因   

默认源无法下载，从阿里云更新下载源