We all have played the card game Blackjack at one time or another. In this card game, we are dealt two cards, one face up and the other face down. The dealer also gets two cards, one face up and the other face down.
Dr.
Mark Armfelt, DVM, DABVP; Adjunct Faculty, Department of Veterinary Preventive
Medicine, Ohio State University; Technical Service Representative, Monsanto
Dairy Business (top of page)