there _ _ baskball on the desk.(否定句填空)

问题描述:

there _ _ baskball on the desk.(否定句填空)
_ _ a ball behind the door?Yes,_ _.(疑问句填空,并肯定回答)
there are _two_ computers in the office.(划线处提问)
_ _ computers _ _ in the office?

isn't any
Is there...there is
How many...are there