參考別人的，自己記錄一下，怕丟失
修改方法：vim /etc/apt/sources.list，然後新增下面對應的程式碼區
中科大映象源
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-updates main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-backports main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-security main restricted universe multiverse
deb https://mirrors.ustc.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
deb-src https://mirrors.ustc.edu.cn/ubuntu/ bionic-proposed main restricted universe multiverse
臺灣的官方源
deb http://tw.archive.ubuntu.com/ubuntu karmic main restricted universe multiverse
deb http://tw.archive.ubuntu.com/ubuntu karmic-security main restricted universe multiverse
deb http://tw.archive.ubuntu.com/ubuntu karmic-updates main restricted universe multiverse
deb http://tw.archive.ubuntu.com/ubuntu karmic-backports main restricted universe multiverse
deb http://tw.archive.ubuntu.com/ubuntu karmic-proposed main restricted universe multiverse
deb-src http://tw.archive.ubuntu.com/ubuntu karmic main restricted universe multiverse
deb-src http://tw.archive.ubuntu.com/ubuntu karmic-security main restricted universe multiverse
deb-src http://tw.archive.ubuntu.com/ubuntu karmic-updates main restricted universe multiverse
deb-src http://tw.archive.ubuntu.com/ubuntu karmic-backports main restricted universe multiverse
deb-src http://tw.archive.ubuntu.com/ubuntu karmic-proposed main restricted universe multiverse
台灣 臺灣大學更新伺服器
deb http://ubuntu.csie.ntu.edu.tw/ubuntu/ karmic main restricted universe multiverse
deb-src http://ubuntu.csie.ntu.edu.tw/ubuntu/ karmic main restricted universe multiverse
deb http://ubuntu.csie.ntu.edu.tw/ubuntu/ karmic-updates main restricted universe multiverse
deb-src http://ubuntu.csie.ntu.edu.tw/ubuntu/ karmic-updates main restricted universe multiverse
deb http://ubuntu.csie.ntu.edu.tw/ubuntu/ karmic-backports main restricted universe multiverse
deb-src http://ubuntu.csie.ntu.edu.tw/ubuntu/ karmic-backports main restricted universe multiverse
deb http://ubuntu.csie.ntu.edu.tw/ubuntu/ karmic-security main restricted universe multiverse
deb-src http://ubuntu.csie.ntu.edu.tw/ubuntu/ karmic-security main restricted universe multiverse
deb http://ubuntu.csie.ntu.edu.tw/ubuntu/ karmic-proposed main multiverse restricted universe
deb-src http://ubuntu.csie.ntu.edu.tw/ubuntu/ karmic-proposed main restricted universe multiverse
網易163更新伺服器：
deb http://mirrors.163.com/ubuntu/ karmic main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ karmic-security main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ karmic-updates main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ karmic-proposed main restricted universe multiverse
deb http://mirrors.163.com/ubuntu/ karmic-backports main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ karmic main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ karmic-security main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ karmic-updates main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ karmic-proposed main restricted universe multiverse
deb-src http://mirrors.163.com/ubuntu/ karmic-backports main restricted universe multiverse
sohu 更新伺服器：
deb http://mirrors.sohu.com/ubuntu/ karmic main restricted universe multiverse
deb http://mirrors.sohu.com/ubuntu/ karmic-security main restricted universe multiverse
deb http://mirrors.sohu.com/ubuntu/ karmic-updates main restricted universe multiverse
deb http://mirrors.sohu.com/ubuntu/ karmic-proposed main restricted universe multiverse
deb http://mirrors.sohu.com/ubuntu/ karmic-backports main restricted universe multiverse
deb-src http://mirrors.sohu.com/ubuntu/ karmic main restricted universe multiverse
deb-src http://mirrors.sohu.com/ubuntu/ karmic-security main restricted universe multiverse
deb-src http://mirrors.sohu.com/ubuntu/ karmic-updates main restricted universe multiverse
deb-src http://mirrors.sohu.com/ubuntu/ karmic-proposed main restricted universe multiverse
deb-src http://mirrors.sohu.com/ubuntu/ karmic-backports main restricted universe multiverse
骨頭兄親自搭建並維護這個Ubuntu源
deb http://ubuntu.srt.cn/ubuntu/ karmic main restricted universe multiverse
deb http://ubuntu.srt.cn/ubuntu/ karmic-security main restricted universe multiverse
deb http://ubuntu.srt.cn/ubuntu/ karmic-updates main restricted universe multiverse
deb http://ubuntu.srt.cn/ubuntu/ karmic-proposed main restricted universe multiverse
deb http://ubuntu.srt.cn/ubuntu/ karmic-backports main restricted universe multiverse
deb-src http://ubuntu.srt.cn/ubuntu/ karmic main restricted universe multiverse
deb-src http://ubuntu.srt.cn/ubuntu/ karmic-security main restricted universe multiverse
deb-src http://ubuntu.srt.cn/ubuntu/ karmic-updates main restricted universe multiverse
deb-src http://ubuntu.srt.cn/ubuntu/ karmic-proposed main restricted universe multiverse
deb-src http://ubuntu.srt.cn/ubuntu/ karmic-backports main restricted universe multiverse
deb http://mirror.lupaworld.com/ubuntu/ubuntu-cn karmic main restricted universe multiverse
Archive.ubuntu.com更新伺服器
deb http://archive.ubuntu.com/ubuntu/ karmic main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ karmic-security main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ karmic-updates main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ karmic-proposed main restricted universe multiverse
deb http://archive.ubuntu.com/ubuntu/ karmic-backports main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ karmic main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ karmic-security main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ karmic-updates main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ karmic-proposed main restricted universe multiverse
deb-src http://archive.ubuntu.com/ubuntu/ karmic-backports main restricted universe multiverse
Mirrors.shlug.org更新伺服器
deb http://cn.archive.ubuntu.com/ubuntu karmic main restricted universe multiverse
deb http://cn.archive.ubuntu.com/ubuntu karmic-security main restricted universe multiverse
deb http://cn.archive.ubuntu.com/ubuntu karmic-updates main restricted universe multiverse
deb http://cn.archive.ubuntu.com/ubuntu karmic-backports main restricted universe multiverse
deb http://cn.archive.ubuntu.com/ubuntu karmic-proposed main restricted universe multiverse
deb-src http://cn.archive.ubuntu.com/ubuntu karmic main restricted universe multiverse
deb-src http://cn.archive.ubuntu.com/ubuntu karmic-security main restricted universe multiverse
deb-src http://cn.archive.ubuntu.com/ubuntu karmic-updates main restricted universe multiverse
deb-src http://cn.archive.ubuntu.com/ubuntu karmic-backports main restricted universe multiverse
deb-src http://cn.archive.ubuntu.com/ubuntu karmic-proposed main restricted universe multiverse
Mirror.lupaworld.com更新伺服器
deb http://mirror.lupaworld.com/ubuntu karmic main restricted universe multiverse
deb http://mirror.lupaworld.com/ubuntu karmic-security main restricted universe multiverse
deb http://mirror.lupaworld.com/ubuntu karmic-updates main restricted universe multiverse
deb http://mirror.lupaworld.com/ubuntu karmic-backports main restricted universe multiverse
deb http://mirror.lupaworld.com/ubuntu karmic-proposed main restricted universe multiverse
deb-src http://mirror.lupaworld.com/ubuntu karmic main restricted universe multiverse
deb-src http://mirror.lupaworld.com/ubuntu karmic-security main restricted universe multiverse
deb-src http://mirror.lupaworld.com/ubuntu karmic-updates main restricted universe multiverse
deb-src http://mirror.lupaworld.com/ubuntu karmic-backports main restricted universe multiverse
deb-src http://mirror.lupaworld.com/ubuntu karmic-proposed main restricted universe multiverse
ubuntu 10.04源
deb http://mirrors.163.com/ubuntu/ lucid main universe restricted multiverse
deb-src http://mirrors.163.com/ubuntu/ lucid main universe restricted multiverse
deb http://mirrors.163.com/ubuntu/ lucid-security universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ lucid-security universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ lucid-updates universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ lucid-proposed universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ lucid-proposed universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ lucid-backports universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ lucid-backports universe main multiverse restricted
deb-src http://mirrors.163.com/ubuntu/ lucid-updates universe main multiverse restricted
以下為充字數內容
Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Venenatis cras sed felis eget velit aliquet sagittis id. Sed tempus urna et pharetra. Donec ultrices tincidunt arcu non sodales neque sodales ut etiam. Parturient montes nascetur ridiculus mus mauris vitae ultricies leo integer. Id consectetur purus ut faucibus pulvinar elementum integer enim. Purus non enim praesent elementum facilisis leo vel fringilla. Quis hendrerit dolor magna eget est lorem ipsum dolor sit. Fusce id velit ut tortor pretium viverra. Orci nulla pellentesque dignissim enim sit amet venenatis. Volutpat odio facilisis mauris sit amet massa vitae tortor condimentum. Sed arcu non odio euismod. Interdum varius sit amet mattis. Venenatis a condimentum vitae sapien pellentesque habitant morbi tristique senectus. Urna cursus eget nunc scelerisque viverra mauris in. Congue nisi vitae suscipit tellus mauris. Et sollicitudin ac orci phasellus egestas tellus rutrum tellus.
Lectus vestibulum mattis ullamcorper velit sed ullamcorper. Elit at imperdiet dui accumsan sit amet nulla. Feugiat in ante metus dictum. Dis parturient montes nascetur ridiculus mus. Nunc mattis enim ut tellus elementum sagittis vitae et leo. Ultricies mi eget mauris pharetra. Felis eget velit aliquet sagittis id consectetur purus. Turpis egestas integer eget aliquet nibh praesent tristique magna sit. Feugiat nisl pretium fusce id velit ut tortor pretium. Tristique risus nec feugiat in fermentum posuere urna nec tincidunt. Non arcu risus quis varius quam quisque. Libero volutpat sed cras ornare. Posuere lorem ipsum dolor sit. Dolor purus non enim praesent elementum facilisis leo. Mauris a diam maecenas sed enim ut.
Elementum pulvinar etiam non quam lacus suspendisse faucibus interdum. Et netus et malesuada fames. Dui id ornare arcu odio ut sem nulla. Proin libero nunc consequat interdum varius sit. Quam nulla porttitor massa id neque aliquam vestibulum morbi. Ut tristique et egestas quis ipsum suspendisse. A arcu cursus vitae congue mauris. Ut porttitor leo a diam sollicitudin tempor. Tortor dignissim convallis aenean et tortor at. Ac feugiat sed lectus vestibulum mattis ullamcorper velit sed ullamcorper. Habitasse platea dictumst quisque sagittis purus sit.
Semper viverra nam libero justo laoreet sit amet cursus sit. Vel orci porta non pulvinar neque. Maecenas sed enim ut sem viverra aliquet eget sit. Netus et malesuada fames ac turpis egestas integer eget aliquet. Sit amet mattis vulputate enim nulla aliquet porttitor lacus luctus. A cras semper auctor neque vitae tempus quam pellentesque. Ultrices vitae auctor eu augue ut lectus arcu. Id velit ut tortor pretium viverra suspendisse potenti nullam ac. Et malesuada fames ac turpis egestas integer eget aliquet nibh. Egestas fringilla phasellus faucibus scelerisque eleifend donec. At tellus at urna condimentum mattis pellentesque id nibh tortor. Dolor magna eget est lorem ipsum dolor sit. Eget mi proin sed libero enim. Aliquam ultrices sagittis orci a scelerisque purus semper eget duis. Tellus rutrum tellus pellentesque eu tincidunt tortor aliquam.
Felis eget velit aliquet sagittis id consectetur purus ut. Vitae proin sagittis nisl rhoncus mattis rhoncus urna neque. Non quam lacus suspendisse faucibus interdum. Elit scelerisque mauris pellentesque pulvinar. Habitasse platea dictumst vestibulum rhoncus est pellentesque. Eu ultrices vitae auctor eu. Viverra suspendisse potenti nullam ac tortor vitae purus. Nulla pellentesque dignissim enim sit amet venenatis urna cursus eget. Lectus sit amet est placerat in egestas erat imperdiet sed. Gravida neque convallis a cras semper auctor neque vitae. Morbi non arcu risus quis varius quam quisque id diam. Quam quisque id diam vel quam elementum pulvinar. Ullamcorper eget nulla facilisi etiam dignissim diam quis enim. Vel elit scelerisque mauris pellentesque pulvinar pellentesque habitant. Vitae congue eu consequat ac felis donec et odio. In nulla posuere sollicitudin aliquam ultrices sagittis orci a. Ligula ullamcorper malesuada proin libero nunc. Maecenas pharetra convallis posuere morbi leo urna. Ut consequat semper viverra nam libero. Sit amet cursus sit amet dictum sit.
亂數假文，英文又稱“Lorem ipsum”，是指一篇常用於排版設計領域的文章，主要的目的為測試文章或文字在不同字型、版型下看起來的效果，通常網站還沒建設好時會出現這段文字。
亂數假文生成器用來生成一篇用於排版設計領域的隨機文章，支援生成英文、簡體中文、繁體中文的亂數假文。
亂數假文相關介紹
Lorem ipsum從西元15世紀開始就被廣泛地使用在西方的印刷、設計領域中，在電腦排版盛行之後，這段被傳統印刷產業使用幾百年的無意義文字又再度流行。由於這段文字以“Lorem ipsum”起頭，並且常被用於標題的測試中，所以一般稱為Lorem ipsum，簡稱為Lipsum。
網站沒有建設完時，也會出現這樣的段落，甚至有些是故意的，包括使用網頁製作軟體，網頁模板等，新建時一般都會出現Lorem ipsum段落
常見的Lorem ipsum起頭如下：
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.
原先大家以為這段拉丁文只是沒有意義的組合，目的是讓閱讀者不要被文章內容所影響，而只專注於觀察字型或版型，並藉此填滿空間。但根據美國拉丁學者Richard McClintock的研究，Lorem ipsum原來起源於西塞羅的《善惡之盡》（De finibus bonorum et malorum）：
Neque porro quisquam est qui dolorem ipsum quia dolor sit amet, consectetur, adipisci velit…
（中譯：無人愛苦，亦無人尋之慾之，乃因其苦…）
為了減少Lorem ipsum的可讀性，並且讓字母出現的頻率與現代英語接近，所以有些版本中部分字母被K、W、Z等拉丁文中沒有的字母替換，或是加入zzril、takimata等字。除了原始的Lorem ipsum版本外，還有幾套新的Lorem ipsum。