Prepositions of place: at, in and on. Usually 'at' a point, 'in' an enclosed space, 'on' a surface.

We arrived [  ] the airport [  ] Birmingham by car, to get [ ] a plane. 

We went [  ] through the door, stopped [  ] the information desk, and sat [  ] the stools there.

[  ] the arrivals hall there were many cafes to sit [  ], so I chose one with a soft chair to sit [  ].

We went [  ] the cafe counter and I choose a cake [  ] a plate and coffee [  ] a cup.

She sat [  ] a stool [  ] the table. I was more comfortable sitting low [  ] my soft chair.