I sent my first e-mail when I was 17. I discovered Google 5 years later. Today I use the Internet all the time. When I was a kid, I never imagined that I would one day send messages using a computer that fits in my backpack. Your experience is probably very different. “Kids are now living in a virtual( 虚拟的 ) world,” says psychologist Patricia Greenfield. She’s director of the Children’s Digital Media Center at the University of California, Los Angeles. Scientists have begun to wonder whether the Internet is good or bad for kids. Nearly 90 percent of 12-to-17-year-olds in the United States use the Internet, according to one recent survey, and about half of these kids use it every day. They visit chat rooms and send e-mails. They go to Websites to get information for homework. As digital technology influences the lives of young people more and more, scientists have begun to wonder: Is the Internet good or bad for kids?” “It’s important to answer that question because the Internet involves so many things,” says Justine Cassell, a media expert at Northwestern University. “ They include networked computer games, news about politics, instant messaging and e-mails to your grandmother.” To add to the uncertainty, more and more students show that the online world can be helpful in some ways and dangerous in others. It can be both an educational resource and, for example, a hiding place for kidnappers. “The bottom line,” Greenfield says, “is that the Internet is a very powerful tool that can be used equally for everyone.”