I used to use buying a tape as a reward for good behavior, but that doesn't work very well any more because he has a lot of them already and he's crazy about the radio.
過去我用買不買錄音帶，當作乖不乖的獎懲，現在效果不大，一方面錄音帶已經夠多，另一方面他現在迷上聽廣播。