Final answer:
Benjamin Franklin's father, Josiah, was chosen as a justice for a certain event or organization when Franklin was a certain age.
Step-by-step explanation:
When Franklin was a boy, at a certain age, Ben's father Josiah is chosen as a _______ for _______.
Based on the information provided, we can infer that the missing words in the question are 'certain' and 'justice' respectively. Ben's father, Josiah, was chosen as a justice for a certain event or organization.