Exercise 2 M10010119

Mug Music Player

Play：放入茶包(代表每種音樂)
Stop：把茶包拿出
Loud←→Quiet：茶包越浸越久，越大聲；傾斜放，即停止加大聲音(比擬泡茶漸濃郁的過程)
Next←→ preview：換茶包