对uos的源进行更换。更换为ubuntu的源_uos添加ubuntu源

1.在/etc/apt下的源文件进行备份

sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak 

2.修改源文件的内容

sudo chmod 777 /etc/apt/sources.list

 vi /etc/apt/sources.list

将以下内容覆盖进去（阿里云的源）

deb http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse  
deb http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse  
deb http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse  
deb http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse  
deb http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse  
deb-src http://mirrors.aliyun.com/ubuntu/ trusty main restricted universe multiverse  
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-security main restricted universe multiverse  
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-updates main restricted universe multiverse  
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-proposed main restricted universe multiverse  
deb-src http://mirrors.aliyun.com/ubuntu/ trusty-backports main restricted universe multiverse 

3.sudo apt-get update

   sudo apt-get upgrade

//出现公钥私钥啥啥啥问题的时候，执行：

sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com 40976EAF437D05B5 3B4FE6ACC0B21F32

然后再次执行sudo apt-get upgrade

4.结束