[单项选择]Ice Cream For Dogs 1. Humans not only love eating ice cream, they enjoy feeding it to their pets(宠物). Market studies show that two-thirds of all dog owners give ice cream to their dogs. Unfortunately, says William Tyznik, an expert on animal nutrition(营养)at Ohio State University, ice cream is not good for dogs. "It has milk sugar in it," he says," which dogs cannot digest very well. " 2. Bothered by that knowledge but aware of the desire of dog owners to please their companions, Tyznik invented a new frozen treat for dogs that, he says, is more nutritious than ice cream—and as much fun to eat. The product, called Frosty Paws, is made of a liquid by-product (副产品) of cheese and milk with the sugar removed. Frosty Paws also contains refined soy flour, water, vegetable oil, vitamins and minerals. It took Tyznik, who has also invented a horse feed (called Tizwhiz)and another dog food (named Tizbits), three years to perfect the Frosty Paws formulas, and two attempts to commercialize it