动物名词单复数区分 — 英语情景题

情景对话：Sam 和 Tom 在学校门口等车时，看到路边有一些动物。请从方框中选择合适的句子补全对话，把序号填在横线上。 方框：A. It's a cat. B. They are dogs. C. Look! One bird. D. It's a rabbit. Sam: (1)________ It is small and it can fly (飞). Tom: What is it? Sam: (2)________ Tom: Look over there! Two animals are running (跑). Sam: Are they cats? Tom: No. (3)________ Sam: And what's under the tree? Tom: (4)________ It has long ears (长耳朵).