A、They enable you to add people you know as friends. B、They offer you a place to build up your account and profile. C、They make

Today let’s talk about social networking. First let’s talk about networks. Networks get things done. Whether it’s sending a letter or lighting your home. Networks make it happen. To get from Chicago to Santa Fe, we need to see the network of roads that will get us there. We see that Chicago is connected to St Louis, which is connected to Dallas which is connected to Santa Fe.
    Of course, people networks can help us with finding jobs, meeting new friends, and finding partners. You know how it works. Bob is your friend, he knows Sally, and Sally’s friend Joe has a job for you. This is a network of people—a social network. The problem with social networks in the real world is that most of the connections between people are hidden. Your network may have huge potential, but it’s only as valuable as the people and connections that you can see.
    This problem is being solved by a type of website called a social networking site.[24]These websites help you see connections that are hidden in the real world. Here’s how it works. You sign up for a free account and fill out your profile. Then, you look for people you know. When you find someone, you click a button that says, "Add as Friend". Once you do this, you and that person have a connection on the website that others can see.
    They are a member of your network, and you are a member of theirs. What’s really cool is that you can see who your friends know, and who your friends’ friends know. You’re no longer a stranger, so you can contact them more easily. This solves a real world problem because your network has hidden opportunities. Social networking sites make these connections between people visible.
    Like a map for a highway, they can show you the people network that can help you get to your next destination, whether it’s a job, a new partner, or a great place to live. Your network is suddenly more useful. You can get started at these sites, LinkedIn, Facebook, and MySpace.
23. What is the problem with social networks in the real world?
24. How can the social networking sites solve the problem of social networks?
25. What is cool about the social networking websites?