用适当的介词填空 in /on /under /behind/ to/ of /next to

用适当的介词填空 in /on /under /behind/ to/ of /next to
A cat is the tree
Many bananas are the tree
Some pictures are the wall
Li Lei is duty today
I can't see the dog.It's the door
A red bike is the tree
Who's the photo
There is a door the wall
Welcome Hangzhou
This is a photo my family