39、Empty the trash even if told you can’t(强制清空回收站)
open a terminal window and type the following two commands,
(在终端输入:)

    sudo rm -rf ~/.local/share/Trash/{files,info}/

40、Login automatically after boot-up(自动登入系统)
click System ! Administration ! Login Window. Then click the Security tab, and put a check in Enable Automatic Login. From the User dropdown list, select your username. Then click Close
(依次打开“-系统管理-登陆窗口”,在“安全”标签里,勾选“启用自动登陆”,在“用户”的下拉菜单中选择要自动登陆的用户,关闭。)