The Bell Tower is _________ the middle of Xi’an. [ ]

Look! There are many apples _______ the tree and some birds are _______ the tree, too. [ ]

Does anyone know _______ girl with a book in her hand over there?—I’m afraid no one knows.

There are few problems left I believe you can deal with them yourself．

（2007年浙江省第二次五校联考，8）How long do you think ___________ the Microsoft brings out a new product?