When working on proposals, it's not unheard of to bin something by accident. Fear not, any deleted items can quickly be restored with the Better Proposals recycle bin or 'undo' feature.
Here's how to get deleted content back
Click the green 'Add to this page' tab on the right of any page and then click 'Restore deleted items'.
A side-in menu will appear with your recently deleted items in it.
Click the restore button and your deleted material will appear back in your proposal where it came from.