There are many inventions that have caused great changes in the world.Here's a short introduction.For example,Steven J.Sasson invented the digital camera in 1975.Unlike previous cameras,digital cameras don't need to use film and store taken photographs in digital memory cards or internal storage.It also saves a lot more money since you don't need to spend money to buy film.Another important invention is the telephone,created by Alexander Ball in 1876.Now people don't need to send letter or use telegraphs to communicate with others.Whether the receiving person is far away or just in the house right next door to you,you can contact them instantly and effortlessly.Besides having telephones as a communication device,there's also the radio that has the ability of mass communication.Invented in 1895 by Guglielmo Marconi,the radio is used to inform the public of news or broadcast music for entertainment.All three are very important inventions that mark a keystone in the evolving history of humankind.Without these inventions,modern technology may not exist as it does today.
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