Within smartphones, the Internet becomes mobile, and we can do most of the things we do on a typical day without moving around much.    Imagine one day on a weekend. You are at home alone. At 7:50, the phone is ringing for morning hobby classes. You unlock the phone, enter the online classroom and get ready. The teacher is talking about poems. You listen carefully, answer questions and discuss with classmates across the screen.    During a break, you log into a take-out app and order your favorite jiaozi. It is sent to you at your desired time.    In the afternoon, you go over the morning lessons. After sending homework to your teacher by email, you decide to have some fun. You click on a music app icon and choose your favorite songs. After an hour or so, you want to go the nearby park for some fresh air.