input: Write a python function to check if a sentence is in passive or active voice.
  assert check_voice('The work was done by John.') == 'Passive'
  assert check_voice('John did the work.') == 'Active'
  assert check_voice('The project was completed.') == 'Passive'
  assert check_voice('She is singing a song.') == 'Active'
output: def check_voice(sentence):
      passive_indicators = ['was', 'were', 'is', 'are', 'been', 'being']
      if any(word in sentence.split() for word in passive_indicators) and 'by' in sentence:
          return 'Passive'
      return 'Active'