从方框中选择合适的选项补全对话。 A. Are they ducks? B. What are these? C. Are they cows? D. How many cows do you have? : Welcome to my farm. : Wow! Your farm is so big. 【小题1】 : They are pigs. : What about those? 【小题2】 : Yes, they're cows. : 【小题3】 : Twenty. : 【小题4】 : No, they aren't. They are hens. : They are so fat and cute.