rozpatrywany po angielsku:

The police carefully investigated the cause of the accident.

The cause of the accident was being investigated by the police.

John investigated the accident thoroughly.

A research organization investigated the effect.

He has investigated the possibility of cooperation.

The papers found lots of monkey business when they investigated the Recruit scandal.

She investigated the company's output record carefully.

Charles Walcot investigated the magnetic compass bearing sense in pigeons.