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 ot 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 commercialise it. After losing ＄ 25,000 trying to market the invention himself, Tyznik sold the rights to Associated Ice Cream of Westerville, Ohio, which makes the product and packages it in cups. 3. Tyznik claims that Frosty Paws has been tested extensively and that "dogs love it". Of 1,400 dogs that have been offered the product, he says, 89 percent took it on the first try. Three out of four preferred it to Milk-Bone or sausages. The product, which will be available in the ice-cream section of supermarkets, comes in packs of three or four cups, costing between ＄ 1.79. 4. What would happen if a human should mistake Frosty Paws for real ice cream Nothing, says Tyznik. It’s harmless, but frankly, he says, it won’t taste very good. Para 3 ______.