Qidiruv

work on something;

carry on (continue) work;

Work on public conveyance

The spring which is fixed on the main spring and enters work at the loaded vehicle

The pneumatic tire with winter tread pattern for work on snow, wet, dirty and friable roads

You must concentrate on your work (what...on?). sich konzentrieren auf A: Du mußt dich auf deine Arbeit (worauf?) konzentrieren.