Restore Ubuntu from the top of the Panel to the initial state

I believe that many children's shoes are the same as me. I accidentally deleted all the stuff on the top panel, but I found that this tool cannot be added to the Panel. At this time, we can actually restore the upper panel to the initial value:

1. press Alt + F2, enter the following content, and press ENTER
Gconftool -- Recursive-unset/apps/panel

2. press Alt + F2 again, enter the following content, and press ENTER
Rm-RF ~ /. Gconf/apps/panel

3. You have to perform Alt + F2 again, enter the following content, and press Enter.
Pkill gnome-panel

OK ~
Check it out. The Panel has been restored to its initial state.