To view the front app but hide all other apps, press Option-Command-H. Command-H: Hide the windows of the front app.To find the previous occurrence, press Shift-Command-G. Command-G: Find Again: Find the next occurrence of the item previously found.Command-F: Find items in a document or open a Find window.In some apps, you can undo and redo multiple commands. You can then press Shift-Command-Z to Redo, reversing the undo command. Command-V: Paste the contents of the Clipboard into the current document or app.Command-C: Copy the selected item to the Clipboard.
Command-X: Cut the selected item and copy it to the Clipboard.