A、The world of blog writers and blog readers. B、The blogs that are read by so many people. C、The atmosphere created by the blog

Only a few years ago, a "web log" was a little-known way of keeping an online diary. At that time, it seemed like "blogs", as they quickly became known, were only for serious computer geeks. This didn’t last long, though, and within a very short period of time, blogs exploded—blogs were everywhere, and it seemed that almost everyone read blogs, or was a blogger.
    The blogging craze of a couple of years ago now seems to have died down a bit—yet thousands of blogs remain. Now blogs are no longer seen as the exclusive possession of the computer geeks, and are now seen as important and influential sources of news and opinion. So many people read blogs now, that it has even been suggested that some blogs may have been powerful enough to influence the result of the recent US election.
    Blogs are very easy to set up—all you need is a computer, an Internet connection and the desire to write something. The difference between a blog and a traditional Internet site is that a blog is one page consisting mostly of text, with perhaps a few pictures, and importantly, the space for people to respond to what you write. The best blogs are similar to online discussions, where people write in responses to what the blogger has written. Blogs are regularly updated—busy blogs are updated every day, or even every few hours.
    Not all blogs are about politics, however. There are blogs about music, film, sport, books—any subject you can imagine has its enthusiasts typing away and giving their opinions to fellow enthusiasts or anyone else who cares to read their opinions.
    So many people read blogs now that the world of blog writers and blog readers has its own name—the "blogosphere".
    But how influential, or important, is this blogosphere really? One problem with blogs is that many people who read and write them seem only to communicate with each other. When people talk about the influence of the blogosphere, they do not take into account the millions of people around the world who are not bloggers, never read blogs, and don’t even have access to a computer, let alone a good Internet connection.
    Sometimes, it seems that the blogosphere exists only to influence itself, or that its influence is limited to what is actually quite a small community. Blogs seem to promise a virtual democracy—in which anyone can say anything they like, and have their opinions heard—but who is actually listening to these opinions? There is still little hard evidence that blogs have influenced people in the way that traditional mass media(television and newspapers)have the ability to do.
16 What do we learn about blogs?
17 What is the difference between a blog and a traditional Internet site?
18 What is "blogosphere"?
19 What can be estimated about the blogs’ power of influencing people?