Joke: Mental deficiency

Would you mind telling me, Doctor," Bob asked ..."how you detect a mental deficiency in somebody who appears completely normal?" "Nothing is easier," he replied.

"You ask him a simple question which everyone should answer with no trouble.
If he hesitates, that puts you on the track." " Well, What sort of question?" "Well, you might ask him, 'Captain Cook made three trips around the world and died during one of them. Which one?'
Bob thought for a moment, and then said with a nervous laugh, "You wouldn't happen to have another example would you? I must confess I don't know much about history
[Tag]:Mental deficiency
[Time]:7/8/2009