仔细阅读下面的短文，短文中有10个空格或画线句子。请按照每小题括号内的具体要求完成语法填空、词形变化、句子合并、句子改写以及病句改正等。

　　Look, what are those persons up 　　[1]　　(介词)?They are surfing on the Internet．Many of them are part of a new addiction(瘾)called Internet addiction．Internet addicts spend at least thirty to forty hours 　　[2]　　(live)online every week．The use of the Internet can be an addiction like drug(毒品)use．People lose control(控制)of the time they spend on 　　[3]　　(冠词)Internet．

　　For example, one college student was 　　[4]　　(miss)for several days．His friends were worried, and they called the police 　　[5]　　(副词短语)his parents．[6]He was found by the police in a computer lab．(改为主动语态)He was surfing the net for several days straight．

　　[7]A study is done．It shows that about 6％ to 10％ of Internet users become addicted(合并成一个句子)．　　[8]　　(连词)people worry about the teens(青少年)because the Internet is changing the playing field for some of them．They spend more time in cyberspace than in the real? world of friends and family．[9]If the Internet made all the teens care about virtual life instead of real life, our world will be of no hope．(改错)

　　Is “surfing the net” a hobby or an addiction for you? You may have a problem if you have these symptoms(症状)：

　　·You do not go to important family activities or you do not do school work because you like to spend hours on the Internet．

　　·You can’t wait for your next online time．

　　·You plan to spend a short time online, but then you spend several hours．

　　·You go out with your friends less and less．

　　But don’t be 　　[10]　　(pessimist)about your future．