从方框中选择合适的词填空。

think，it，an，on，in，of，It's，Where，know，What

     Look at the picture. It's a picture a room.can you see   the room？I can see an orangethe desk. Can you see  English book on the desk？No，I can't. Is the bag behind(在……后面) the chair？Yes，is.  is the pen？I  it's in the pencil case. Where is the cat？under the desk. What's its name？Sorry，I don't ^.