Excellent Persuasion

As Mark sat at the kitchen table this afternoon trying to decide between doing his homework or dismantling an old telephone, I told him that I was going outside to do some yardwork and wanted him to do his homework. I said, "If your homework isn't done by the time I come back inside, I will take away the phone and all of the stuff you're playing with that's here on the table." He nodded and replied, "Excellent persuasion!" His work was finished when I came back indoors.