问题
填空题
透镜在生活中应用广泛，投影仪的镜头、放大镜都用到了 透镜（选填“凸”或“凹”），不同的是投影仪成的是 像，放大镜成的是 像（均选填“虚”或“实”）。
答案
凸，实，虚
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透镜在生活中应用广泛，投影仪的镜头、放大镜都用到了 透镜（选填“凸”或“凹”），不同的是投影仪成的是 像，放大镜成的是 像（均选填“虚”或“实”）。
凸，实，虚
Museums have changed. They are no longer places that one “should” go to but to enjoy. At a science museum in Canada, you can feel your hair stand on end as harmless electricity passes through your body. At the Children’s Museum in New York, you can play an African drum. There are no “Do Not Touch” sign in some other museums in the USA. More and more museum directors have realized that people learn best when they can become part of what they are seeing. In many science museums, the visitors are encouraged to touch, listen, operate and experiment so as to discover scientific rules for themselves. The purpose is not only to provide fun, but also help people feel at home in the world of science. If people don’t understand science, they will be afraid of it; and if they are afraid of science, they will not make the best use of it. One cause of all these changes is the increase in wealth and spare time. Another cause is that the number of young people grow in the population. Many of them are college students or college graduates. They see things in a new and different way. They want art that they can take part in. The same is true of s  cience and history.The old museums have been changing and the government is encouraging th  e building of new, modern museums. In the States and Canada, there are more than 6000 museums, twice as many as there were 25 years ago.Title: 小题1: __________________________
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