A、Drinking addiction. B、Gambling addiction. C、Internet addiction. D、Drug addiction. C录音中提到，如同过量饮酒和沉迷赌博一样，人们滥用互联网，这个现象被称为网络成瘾症 (I

Students today learn how to use computers as early as age 5 or 6. They are also spending more time online, surfing the web, e-mailing, twittering, playing games, using Facebook, etc. The question I’d like us to consider is, are people spending too much time on their computers? Many or some doctors believe that people can misuse the Internet, the same way people drink too much or gamble too much. They call this problem Internet Addiction Disorder, or IAD for short.
    The doctors have identified seven signs of IAD. The first sign is that a person wants more and more time on the Internet. One hour is not enough; it’s got to be two or three. The second sign relates to what happens to people if they cannot get on the Internet. They might, um, dream about the Internet. During these dreams their bodies might tremble, and their fingers might move as if they were typing. The third sign is that they need to use the Internet to stop these things from happening to their bodies. In the same way that a few drinks will steady an alcoholic, being on the Internet actually improves the way their bodies feel. Fourth, people with IAD use the Internet more often and stay on line longer than they intended. For example, they might go online to check e-mail, but three or four hours later, they are still there, chatting or surfing the web, or whatever. Fifth, people spend a large amount of time doing things related to the Internet. They might, oh, read books about the Internet, for instance, or download new Internet programs, or attend Internet-related conferences. The sixth sign of IAD is that people substitute online time? for social activities. Frankly, they prefer communicating electronically rather than face-to-face. The seventh and last sign is that Internet use becomes more important than almost anything else—showering, school-work, losing a job, feeding children, even eating yourself. They will also lie about how much time they are spending online, and they will keep using the Internet even if they are punished for it.
    Any of this sound familiar? well, if so, don’t panic. Some doctors discount the notion of IAD. They claim that IAD is not the same as drug addiction, because the Internet is a useful tool for getting information and communication. In other words, there is so much to do online that it takes a lot of time. Yet. still, most people agree that it’s not good to spend too much time on the Internet. Everything in moderation, right?
    23. What does IAD refer to in the lecture?
    24. What is a sign of IAD according to the lecture?
    25. What makes some doctors believe that IAD is not worth concern?