请选出段落中的跑题句(1) Spending too much time on the Internet can have a bad effect on children's health. (2) Children need a lot of physical exercise to stay healthy. (3) When they spend a lot of time online, however, they don't get physical exercise. (4) Children can also easily find information on the Internet that is not suitable for their young minds. (5) Parents should encourage their children to turn off the computer and spend time outside playing physically active games.答案：_____