Before you click Begin Quiz, first set the number of words to drill on, up to 40. You must select at least 25 to get extra credit!   Remember for DOS/Windows machines, you click the tab key to check your answer, then any other letter key to get next word, or use the Continue button if that does not work. Usually if you reload the page you will not need to use the Continue button when you restart the drill. On Macs you can use the tab key both times.  DO NOT USE THE ENTER KEY!! IF SOMEHOW THE PROGRAM BEGINS TO MALFUNCTION SERIOUSLY, IT IS BEST TO CLOSE THE WINDOW AND RELOAD THE PAGE.