Переведите на английский язык следующие словосочетания, употребляя предлоги on или at. На полке, на подоконнике, на скамейке,

On the shelf, on the windowsill, on the bench, at the factory, on the wall, at the station, on the platform, on the floor, on the roof, at the exhibition, at a stop, on the ground, at a concert, on a blackboard, at a lesson, on a bridge, at a stadium , on the snow, on the grass, at work.