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阅读理解 We all know that many inventions have changed our life a lot. They play important roles in our daily life. Here are some interesting inventions.Morpher People refuse to wear helmets because they're thick and heavy. Morpher is a bike helmet made of plastic. It is just as strong as traditional helmets, but it can be folded almost completely flat, making it easier to carry. Morpher may be available for sale in stores in the near future.HyperAdapt Have you ever seen the movie Back to the Future? Maybe everyone wants the pair of shoes in the movie that can tighten or loosen by themselv 清朝前期为巩固统一的多民族国家和捍卫国家主权作了哪些努力？