A、They can inform their friends of what is happening in their lives. B、They can present political and other ideas freely. C、They

A "blogger" is a person who writes on an Internet computer website called a "blog".[19]The word "blog" is a short way of saying Web log, or personal website. Anyone can start a blog, and they can write about anything they like. There are millions of blogs on the Internet today. They provide news, information and ideas to many people who read them. They contain links to other websites. And they provide a place for people to write their ideas and react to the ideas of others. A research company called Perseus has studied more than 3,000 Web logs. It says that blogs are most popular with teenage girls. They use them to let their friends know what is happening in their lives. The study also says that more than 100,000 bloggers stopped taking part in the activity after a year. However, some people develop serious blogs to present political and other ideas. At the same time, some long-standing blogs have ended. Last week, blogging leader Dave Winer closed his free blog service, weblogs.com. He says the site became too costly to continue. He started the blog four years ago, and thousands of people had written on it. They are now upset because they did not know that the site was closing. One blog that is still going strong is called Rebecca’s Pocket. Rebecca Blood created the website in 1999. She wrote about the history of blogs on the site. That article led to a book called The Weblog Handbook. It has been translated into four languages so far.
19. What’s a blog?
20. Why are blogs most popular with teenage girls?
21. What do we learn about Rebecca?