When you install Ubuntu 18.04, you won't have Trash in the Dock (Launcher). Instead, it's in the Desktop, and when you mount a volume, it appears in the Desktop; And it's a little messy if you have another stuff on your Desktop.
So I downloaded tweak-tool, there's an option to remove the trash icon and mounted volumes from Desktop.
How can I set the trash and mounted volumes to appear on the Dock just like previous versions of Ubuntu?