Answer: "The country had been served for the past eleven years by the person without them being exhausted".
Explanation:
In a passive voice, the subject is the one that the action is being done on instead of the one doing the action as is the case in the above sentence which is active voice. For instance, the person in the sentence is doing the action of serving the country.
In passive voice, the action will be done to the person. It would come out as:
"The country had been served for the past eleven years by the person without them being exhausted".
Notice how the action is now being done to the person.
