句型What is it? It's a... — 英语情景题

Sam 和 Amy 在宠物店里玩猜动物游戏。请补全对话中所缺的句子（每空一词）。 Sam: Look! There is a small animal in the box. What (1)________ it? Amy: Is it a cat? Sam: No, it isn't. It has long ears. Guess again! Amy: Oh, I know! (2)________ a rabbit! Sam: Great! Now you ask me. There is a big animal over there. What is (3)________? Amy: It's an elephant!