Blog is getting more and more popular among the teenagers these days. There are some advantages and disadvantages. For example, we can speak or write freely on the blog. We can also share something happy or unhappy with our friends. If we have any difficulties or problems in our study or life, we can write it down in our blog, too. Maybe some people will give us useful suggestions (advice). But Internet is not always useful. Sometimes it’s not safe. If you spend a long time online, it’s bad for your eyes. And surfing on the internet also wastes lots of time.