Sound Puzzle

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Across
  1. 3. back and forth movement of a body in air is called ___ motion
  2. 6. ____ determines the loudness of vibration
  3. 7. time taken to complete one vibration or oscillation
Down
  1. 1. SI unit of measurement of amplitude
  2. 2. sound cannot travel through ____
  3. 4. sound travels fastest in ___ medium
  4. 5. SI unit of measurement of frequency