Think back,I have been using cellphone for more than three years.It seems to be that I almost can't leave it now.I often was under the illusion that it's shaking in my pocket.
An idea came out last night suddenly.What if I leave my phone closed for several days?As the exam of mechanics of materials is just coming and I almost know nothing about it,I have to fling myself into the review body and soul.Well,why not have a try~