题干

某研究性学习小组调查发现,甲、乙两工厂排放的污水各含下列离子Ag+、Ba2+、Na+、Cl、CO32、NO3中的三种离子,若两厂单独排放都会造成严重的水污染,如将两厂的污水按一定比例混合,沉淀后污水便会变成无色澄清只含硝酸钠而排放,污染程度会大大降低,关于污染源的分析,你认为正确的是(   )

A:CO32和NO3可能来自同一工厂

B:Cl和CO32不在同一工厂

C:Ag+和Na+不在同一工厂

D:Na+和NO3来自同一工厂

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C

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    A new generation addiction is quickly spreading all over the world. Weboholism, a twentieth century disease, affects people from different ages. They surf the net, use email and speak in chat rooms. They spend many hours on the computer, and it becomes a compulsive habit. They cannot stop, and it affects their lives.

    Ten years ago, no one thought that using computers could become compulsive behavior that could affect the social and physical life of computer users. This obsessional behavior has affected teenagers and college students. They are likely to log on computers and spend long hours at different websites.

    They become hooked on computers and gradually their social and school life is affected by this situation. They spend all free time surfing and don't concentrate on homework, so this addiction influences their grades and success at school. Because they can find everything on the websites, they hang out there. Moreover, this addiction to websites influences their social life.

    They spend more time in front of computers than with their friends. The relation with their friends changes. The virtual life becomes more important than their real life. They have a new language that they speak in the chat rooms and it causes cultural changes in society.

    Because of the change in their behavior, they begin to isolate themselves from the society and live with their virtual friends. They share their emotions and feelings with friends who they have never met in their life. Although they feel confident on the computer, they are not confident with real live friends they have known all their life. It is a problem for the future. This addictive behavior is beginning to affect all the world.