Some of the exercises have multiple correct answers.
3.1 Classes include league, team, game, inning, player, position, plate appearance, and umpire.
3.2 Classes include health spa, room, therapist, treatment, customer, and appointment. There are additional subtle classes such as work session (contiguous hours of work for a therapist on a particular day, such as 9 AM to 5 PM on March 14, 2010) and payment.
3.3 Classes include Auction, Auctionltem, Bid, Bidder, Feedback, ItemCategory, PaymentMethod, Reply, and Seller.
3.4 Classes include Menu, Menultem, Restaurant, ItemCategory (Appetizer, Salad, Entree, Beverage), and EatingTime (breakfast, lunch, dinner).
3.5 Here is a determination as class or attribute and a brief explanation ...