Before you click Begin Quiz, first set  number of words to drill on, up to 18. Select at least 18 to get extra credit!   For DOS/Windows machines, click the tab key to check answer, then any other letter key to get next word, or use the Continue. Usually if you reload page you will not need to use the Continue button when you restart. On Macs you can use the tab key both times.  DO NOT USE ENTER KEY!! IF THE PROGRAM  MALFUNCTIONS SERIOUSLY, IT IS BEST TO CLOSE THE WINDOW AND RELOAD PAGE. If, after you have gone through a drill, you lose the score, click Show score again.