the boy would ____ the old man a fraud.此处的prove能用show

the boy would ____ the old man a fraud.此处的prove能用show
High in the Himalayan mountains lived a wise old man.
Periodically,he ventured down into the local village to entertain the villagers with his special knowledge and talents.One of his skills was to "psychically" tell the villagers the contents in their pockets,boxes,or minds.
A few young boys from the village decided to play a joke on the wise old man and discredit his special abilities.
One boy came up with the idea to capture a bird and hide it in his hands.He knew of course,the wise old man would know the object in his hands was a bird.
The boy devised a plan.
Knowing the wise old man would correctly state the object in his hands was a bird,the boy would ask the old man if the bird was dead or alive.If the wise man said the bird was alive,the boy would crush the bird in his hands,so that when he opened his hands the bird would be dead; if the wise man said the bird was dead,the boy would open his hands and let the bird fly free.So not matter what the old man said,the boy would prove （此处的prove能用show ） the old man a fraud