Ubuntu使用阿里云源，解决下载速度慢问题。

更换ubuntu源

原文地址：http://www.cnblogs.com/microman/p/6109370.html

在终端中修改方法：

sudo cp /etc/apt/sources.list /etc/apt/sources.list.backup #备份当前也就是默认官方的源列表

sudo gedit /etc/apt/sources.list #修改sources.list文件中源的列表，删除全部内容，替换为国内源地址。 保存编辑好的文件。

sudo apt-get update #更新源列表，换源后必须执行

国内源列表：本人试用过的比较快的源

deb http://mirrors.aliyun.com/ubuntu/ trusty main multiverse restricted universe

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

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

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

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

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

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

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

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

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