摘要
想象一下典型的大学课堂：其中必然会有目不转睛盯着老师的“学霸”，也会有蒙头大睡的“特困生”，不会有交头接耳、制造噪音的“小蜜蜂”。
The screen to my left displayed my classmate＇s Facebook as she scrolled through hundreds of her friends＇ photos： To my right, a student was shopping for dresses from the Lilly Pulitzer store.
