根据对话内容,在每个空白处填入一个适当的词,使对话完整
A：(1)________ ,Jim!There's a big bag under the tree.
B：What's in (2)__________?
A:I (3)__________ know.I guess (4)_______ are some books in it.
B:(5)_________,I think there (6)_________ a football.
A:(7)________ go and open it.
B:Ah,there are some books and a football.
A:Oh,there's a (8)_______ on the bag-David Smith.
B:It's (9)________.Let's go and give him (10)_________ bag.
A:Great!Let's go!