A、Stores on the web. B、Large commercial web sites. C、Small commercial web sites. D、Public government web sites. B短文中提到These web

This week some big internet sites were so busy that they stopped working. Hackers or people who break into other people’s computers did it. Experts think programs called Tribal Village were used.
    The programs worked like time bombs. The hackers put software on other people’s computers. The people do not even know. The software just sits and waits until the hacker starts it. When the hacker wants, all the computers call the same web site. This week Yahoo, Amazon and CNN were called.
    The costs are growing. These web sites make money from advertising. People go to the web sites for information and news. If the web site is not, working, they will go to other sites.
    Yahoo got many calls. It was like 104 million people dialing in at once.
    The website AntiOnline put the software on its site. They hope someone will make a fix.
    The only way to stop the hackers is to stop them from getting into computers. Now it is easy to get into many computers.
    Webmasters are in a tough spot. The goal is to have a site open and easy to reach. This also makes them open to hackers.
    Why do hackers do this? Probably because other hackers will praise them. The hackers could also be sick and tired of the commercialization of the Internet. 5o far all of the targets have been very large, mid very commercial.