Test Your Knowledge!

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Across
  1. 4. Where Edison was born
  2. 5. The code of telegraphs
  3. 7. Instrument for reproducing sounds
  4. 8. Telegraph that sends two messages in each direction
Down
  1. 1. Edison’s first name
  2. 2. A device that takes pictures
  3. 3. Something Edison always did
  4. 6. A telegraph that sends one message in each direction