方法一、通過圖形化界面跟換軟件源
進(jìn)入設(shè)置：點(diǎn)擊software&updates
選擇download from，點(diǎn)擊展開，選擇others
通過手動(dòng)查找列表或者切換至推薦服務(wù)器
通過自動(dòng)檢測，將軟件源切換到ustc
進(jìn)入/etc/apt/sources.list查看軟件源：
nano /etc/apt/sources.list
軟件源已經(jīng)切換到ustc
方法二、
檢驗(yàn)軟件源：
1.備份原始源文件sources.list
桌面打開終端，執(zhí)行命令：sudo? cp?
/etc/apt/sources.list? ? /etc/apt/sources.list.bak
2.修改源文件sources.list
（1）終端執(zhí)行命令：sudo?
?chmod? ?777? ?/etc/apt/sources.list更改文件權(quán)限使其可編輯；
（2）執(zhí)行命令：sudo?
?nano? ?/etc/apt/sources.list打開文件進(jìn)行編輯；
（3）刪除原來的文件內(nèi)容，復(fù)制下面的任意一個(gè)到其中并保存（常用的是阿里源和清華源，推薦阿里源，內(nèi)容可以去博客復(fù)制）；
阿里源：
debhttp://mirrors.aliyun.com/ubuntu/?bionic main restricted universe multiverse
debhttp://mirrors.aliyun.com/ubuntu/?bionic-security main restricted universemultiverse
debhttp://mirrors.aliyun.com/ubuntu/?bionic-updates main restricted universemultiverse
debhttp://mirrors.aliyun.com/ubuntu/?bionic-proposed main restricted universemultiverse
debhttp://mirrors.aliyun.com/ubuntu/?bionic-backports main restricteduniverse multiverse
deb-srchttp://mirrors.aliyun.com/ubuntu/?bionic main restricted universemultiverse
deb-srchttp://mirrors.aliyun.com/ubuntu/?bionic-security main restricted universemultiverse
deb-srchttp://mirrors.aliyun.com/ubuntu/?bionic-updates main restricted universemultiverse
deb-srchttp://mirrors.aliyun.com/ubuntu/?bionic-proposed main restricted universemultiverse
deb-src http://mirrors.aliyun.com/ubuntu/?bionic-backportsmain restricted universe multiverse
清華源：
debhttps://mirrors.tuna.tsinghua.edu.cn/ubuntu/?bionic main restricteduniverse multiverse
deb-srchttps://mirrors.tuna.tsinghua.edu.cn/ubuntu/?bionic main restricteduniverse multiverse
debhttps://mirrors.tuna.tsinghua.edu.cn/ubuntu/?bionic-updates mainrestricted universe multiverse
deb-srchttps://mirrors.tuna.tsinghua.edu.cn/ubuntu/?bionic-updates mainrestricted universe multiverse
debhttps://mirrors.tuna.tsinghua.edu.cn/ubuntu/?bionic-backports mainrestricted universe multiverse
deb-srchttps://mirrors.tuna.tsinghua.edu.cn/ubuntu/?bionic-backports mainrestricted universe multiverse
debhttps://mirrors.tuna.tsinghua.edu.cn/ubuntu/?bionic-security mainrestricted universe multiverse
deb-srchttps://mirrors.tuna.tsinghua.edu.cn/ubuntu/?bionic-security mainrestricted universe multiverse
debhttps://mirrors.tuna.tsinghua.edu.cn/ubuntu/?bionic-proposed mainrestricted universe multiverse
deb-srchttps://mirrors.tuna.tsinghua.edu.cn/ubuntu/?bionic-proposed mainrestricted universe multiverse
163源：
debhttp://mirrors.163.com/ubuntu/?bionic main restricted universe multiverse
debhttp://mirrors.163.com/ubuntu/?bionic-security main restricted universemultiverse
deb http://mirrors.163.com/ubuntu/?bionic-updatesmain restricted universe multiverse
debhttp://mirrors.163.com/ubuntu/?bionic-proposed main restricted universemultiverse
debhttp://mirrors.163.com/ubuntu/?bionic-backports main restricted universemultiverse
deb-src http://mirrors.163.com/ubuntu/?bionicmain restricted universe multiverse
deb-srchttp://mirrors.163.com/ubuntu/?bionic-security main restricted universemultiverse
deb-srchttp://mirrors.163.com/ubuntu/?bionic-updates main restricted universemultiverse
deb-srchttp://mirrors.163.com/ubuntu/?bionic-proposed main restricted universemultiverse
deb-srchttp://mirrors.163.com/ubuntu/?bionic-backports main restricted universemultiverse
3.更新源
桌面終端執(zhí)行命令：sudo apt update更新軟件列表，換源完成。
