I'm reading a book about anti-gravity. It's impossible to put down!
Explanation: The joke plays on 'put down' meaning both to physically place something down (which would be impossible with anti-gravity) and to stop reading an engaging book.
I'm reading a book about anti-gravity. It's impossible to put down!
Explanation: The joke plays on 'put down' meaning both to physically place something down (which would be impossible with anti-gravity) and to stop reading an engaging book.