M7 U1ReadingThe evolution of video and sound devices
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the evolution of video and sound devices  Titleshortly afterwards   L4contributed to the development of TV     L6was very primitive and had many drawbacks  L8made important breakthroughs    L9in the late 1920s and early 1930s    L10TVs use many of the principles    L10constructed the first colour TV   L12regular colour TV broadcasts were delayed  L15