is / are 与主语的单复数一致 — 英语情景题

情景对话：Sam 和 Tom 在农场里参观。（补全对话，每空一词） Sam: Welcome to my uncle's farm, Tom! Tom: Wow, it's big. What can you see over there? Sam: I can see some horses. There (1)________ five horses near the river. Tom: Look! What's in the tree? Sam: There (2)________ a bird in the tree. Tom: I can see some ducks too. How many ducks are there? Sam: There (3)________ eight ducks on the lake.