Do modern JWs not already know that?
Questions should ecourage the JW to go and do research and find answers they were not expecting. I recently asked a cocky JW a question about Jeremiah 25:12. He took it as a challenge to find out the answer. That was two months ago and he hasn't been back, so I guess it wasn't as easy as he thought. When/if I see him again, I won't be asking a different question, I'll be asking the same one.