Listen to the passage. Fill in the blanks with the information you have heard.[音频]1) The chicken is the most commonly1, with a worldwide population of more than 19 billion in 2011.2) A person can identify the different types of chickens by their size,2, feather size, skin color, 3, and egg color.3) Chickens are4and live together in flocks. A flock of chickens containing only females will still 5, but the eggs will never grow into6 . They raise their young7and take turns keeping the eggs warm.4) Popular chicken dishes include8, fried chicken, chicken soup,9, and Gong Bao chicken.