on the sofa还是in the sofa on the bed还是in the bed on the chair

on the sofa还是in the sofa on the bed还是in the bed on the chair还是in the chair
on the sofa还是in the sofa on the bed还是in the bed on the chair还是in the chair?急!~~~在什么情况下用in什么情况下用on呢?请高人指点啊···