阅读理解。 The Internet brings us many advantages. With the Internet, people can send and receive e-mails. On the Internet, people can skim over news. Using the Telnet, the user anywhere on the Internet can log into any other machine on which he has an account. It is possible to use the FIP program to copy files from one machine on the Internet to another. But the Internet also brings us troubles. Internet use seems to cause a fall in psychological (心理的) health, according to research at Camegie Mellon University. Even people who spent just a few hours a week on the Internet experienced more depression and loneliness than those who logged on less often, the two-year study showed. And it wasn't that people who were already feeling bad spent more time on the Internet, but that using the Net actually seemed to cause the bad feelings. Researchers are puzzled over the results, which were completely opposite to what they had expected. They expected that the Net would prove socially healthier than television, since the Net allows users to choose their information and to communicate with others. The fact that Internet use reduces time used for family and friends may be the reason for the drop in health, researchers said. Faceless, bodiless'virtual' (虚拟的) communication may be less psychologically satisfying than actual conversations, and the relationships formed through it may not be so deep. Another possibility is that exposure to the wider world through the Net makes users less satisfied with their lives. 'But it's important to remember this is not about the technology; it's about how it is used,' said one of the researchers. 'It really points to the need for considering social factors (因素) when you design new inventions.' 1. The writer mainly wants to tell us that _____. A. the Internet can bring people many advantages B. the Internet use may cause psychological problems C. the Internet users are not satisfied with their lives D. we shouldn't use the Internet 2. Why are the researchers puzzled over the results? A. Because the results were completely different from what they had thought. B. Because the Net proved socially healthier than television. C. Because the Internet users were all healthier. D. Because the Internet users experienced less depression and loneliness. 3.What may be the reasons why the Internet use causes a fall in psychological health? A. Internet use reduces time used for family and friends. B. Virtual communication is less psychologically satisfying than actual conversations. C. Exposure to the wider world through the Net makes users less satisfied with their lives. D. All the above. 4. What does the underlined part in the last paragraph mean? A. What matters is not the technology but how it is used. B. This passage is not about the technology but about how it is used. C. We should remember to learn about the technology. D. We should remember to learn how to use computers.