Debian9如何解决apt-get update提示错误

1.输入该命令按回车键：`cd /etc/apt`

2.mv sources.list sources.list.back，输入该命令按回车键

3.输入该命令按回车键：`vi sources.list`

4.按“i”进入插入模式，输入以下内容，然后按“ESC”键输入wq按回车键保存退出vi编辑 deb http://archive.debian.org/debian stretch main deb-src http://archive.debian.org/debian stretch main deb http://archive.debian.org/debian-security stretch/updates main deb-src http://archive.debian.org/debian-security stretch/updates main  

5.输入该命令按回车键可以正常执行：`apt-get update -y`