动物名词单复数区分 — 英语情景题

情景对话：Tom 和 Lily 在公园里散步，看到了一些动物。请从方框中选择合适的句子补全对话，将序号填在横线上。 方框：A. It's a bird. B. They are ducks. C. Look! A rabbit! Tom: (1)________ Lily: Where? Oh, it's small and white. It's cute! Tom: Look at the tree. What is it? Lily: (2)________ It can sing. Tom: And what are those on the river? Lily: (3)________ They can swim.