When Peter sees a truck at the grocery store with a cow painted on the back doors, he asks the driver if there are cows in his truck. The driver replies, No cows, Sonny, just milk. On and on again Peter asks truck drivers if they are carrying milk--until the very last truck he sees lumbering down a country road. When Peter asks, the driver has a surprise for him. Jaunty pictures help this cumulative tale roll right along. Full color.