Ключевые слова: animal, bird, black, causality, chicken, country, debate, design, dilemma, domestic, ecological, egg, eggshell, evolution, farm, feather, female, fertility, food, fowl, gastronomy, hen, illustration, life, meat, motherhood, natural, nutrition, outdoors, oval, philosophy, poultry, proof, protein, quality, question, radiography, rays, researchers, riddle, rural, sale, shell, symbol, useful, vitamins, white, wings,