Why did the tomato turn red? because it saw some russian dressing in your liverwurst sandwich. . . What's gray, has four legs, a trunk, and loves peanuts? a mouse packing a picnic with a peanut butter and carrot sandwich. . . When is a sandwich like the Red Baron's airplane? when it is a triple decker. . . All these riddles, plus FACTS (the world's longest sausage, the first canned food, a recipe for stuffed camel a la Bedouin) and instructions for making cold sandwiches (ham and cream cheese; cottage cheese, cucumber and radish; tuna hero). Not exactly a filling combination, but except for an over-reliance on mayonnaise, the food is healthy enough--lots of dark bread and (thank goodness) no marshmallows or ketchup. A light but pleasant snack.