问题
填空题
远视眼镜对光线有______作用（会聚/发散）．若用焦距为10cm的凸透镜作放大镜，物体离凸透镜中心的距离应______10cm．（大于/等于/小于）
答案
由于远视眼镜是凸透镜，故对光线有会聚作用；放大镜是利用了凸透镜的物距小于焦距时，能成放大、正立的虚像的成像原理．
故本题答案为：会聚；小于．
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远视眼镜对光线有______作用（会聚/发散）．若用焦距为10cm的凸透镜作放大镜，物体离凸透镜中心的距离应______10cm．（大于/等于/小于）
由于远视眼镜是凸透镜，故对光线有会聚作用；放大镜是利用了凸透镜的物距小于焦距时，能成放大、正立的虚像的成像原理．
故本题答案为：会聚；小于．
| 阅读理解。 下面文章中有5处(第1-5题)需要添加小标题。请从以下选项(A、B、C、D、E和F)中选出适合各段意思的小标题，选项中有一项是多余选项。 | |
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| 1. _______ With the arrival of the age of "information economy", intellectual work is becoming a more important source of wealth than manufacturing.Organizations in all walks of life are doing more to spread their information. So people of the Public Relations are hired to speak for them. A lot of our news is actually collected from press releases and reports of events intentionally staged for journalists. In the information age, journalists spend their time, not investigating, but passing on the words of a spokesperson. 2. _______ There is a joke in the novel Scoop about the newspaper's owner, Lord Copper. The editors can never disagree with him. When he's right about something they answer "definitely", and when he's wrong they say "to some extent, Lord Copper." It seems reasonable to suppose that, in the real world, the opinions of such powerful people still influence the journalists and editors who work for them. 3. _______ In countries where the news is not officially controlled, it may be provided by commercial organizations who depend on advertising. The news has to attract viewers and maintain its audience ratings. I suspect that some stories get air-time just because there happen to be exciting pictures to show. In Britain, we have the tabloid newspapers which millions of people read simply for entertainment. There is progressively less room for historical background, or statistics, which are harder to present as a sensational story. 4. _______ There is an argument that with spreading access to the internet and cheap technology for recording sound and images we will all be able to find exactly the information we want. People around the world will be able to publish their own eye-witness accounts and compete with the widely-accepted news-gatherers on equal terms .But what it will mean also is that we'll be subjected to a still greater amount of nonsense and lies. Any web log may contain the latest information of the year, or equally, a made-up story that you will never be able to check. 5. _______ Maybe the time has come to do something about it, and I don't just mean changing your choice of TV channel or newspaper. In a world where everyone wants you to listen to their version, you only have two choices: switch off altogether or start looking for sources you can trust. The investigative journalist of the future is everyone who wants to know the truth. |