C Look, read and tick
1
　　　____a It's on the desk .
　　　____b It's on the chair .
2
　　　____a It's under the desk .
　　　____b It's behind the door .
3
　　　____a She is by the tree .
　　　____b She is behind the tree .
4
　　　____a Beibei is by the tree.
　　　____b Beibei is in the tree.