如果你频繁地在你的系统中安装/卸载，那么不时地清理一下你的系统是十分必要的。
在终端中执行如下命令：
sudo apt-get autoremove
屏幕输出是这个样子的：
Reading package lists… Done
Building dependency tree
Reading state information… Done
The following packages were automatically installed and are no longer required:
libcommoncpp2-1.5.3-0
The following packages will be REMOVED
libcommoncpp2-1.5.3-0
0 upgraded, 0 newly installed, 1 to remove and 29 not upgraded.
Need to get 0B of archives.
After unpacking 688kB disk space will be freed.
Do you want to continue [Y/n]?
输入“Y”就可以删除这些包。