（在home目录下新建一个文件夹library（我给你建好了，解压就行），用来安装各种库文件）

先换源（国外的不用换源）

备份

sudo cp /etc/apt/sources.list /etc/apt/sourses.list_bk

修改源

sudo gedit /etc/apt/sources.list

将原所有内容删除，添加以下内容:

deb http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiversedeb http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted universe multiversedeb http://mirrors.aliyun.com/ubuntu/ bionic-updates main restricted universe multiversedeb http://mirrors.aliyun.com/ubuntu/ bionic-proposed main restricted universe multiversedeb http://mirrors.aliyun.com/ubuntu/ bionic-backports main restricted universe multiversedeb-src http://mirrors.aliyun.com/ubuntu/ bionic main restricted universe multiversedeb-src http://mirrors.aliyun.com/ubuntu/ bionic-security main restricted univ