vim的块模式 https://www.cnblogs.com/luosongchao/p/3193153.html
安装搜狗输入法 http://blog.sciencenet.cn/blog-3308665-1114148.html
备份ubuntu https://blog.csdn.net/sinat_27554409/article/details/78227496
设置root密码 https://blog.csdn.net/u012301841/article/details/73692426