Preposition of Place: In and On

They have lots of pictures _____ their fridge.

We put the old books _____ a box.

Last summer we stayed in a cabin _____ a lake.

My office is _____ the 20th floor, so I take the lift.

There are important Roman ruins _____ Jordan.

Their house is _____ the James River.

Buckingham Palace is _____ London.

Her flat is _____ the sixth floor.

Please put the flowers _____ the table.

I'll meet you _____ the bus stop.