Change the active voice into passive voice? 1-the doctor asked the priest a question? 2-the Farmers have picked coffee beans? 3-man cannot avoid natural disasters.
Make the verb a form of "to be."
The doctor was asked a question by the priest.
The coffee beans were picked by the farmer.
Natural disasters cannot be avoided by man.
Any time your predicate verb is a form of "to be" (am, is, are, was, were, do, did, does, be, being, been, have, has, had), you are using the passive voice.