When considering changing the content of a cell which button should you press to leave the cell as it originally was

When considering changing the content of a cell you should press CTRL + Z to leave the cell as it originally was.

To undo an action just:

Press Ctrl+Z until you've fixed your mistake.

Or press Alt+Backspace to do the same thing.

If you prefer your mouse, click Undo on the Quick Access Toolbar.

answer; i believe the answer is tls,transport layer security;