input: Write a python function to classify a given text into 'sports' or 'science' category based on word features.
  assert classify_text('Football is a team sport popular all over the world')=='sports'
  assert classify_text('Molecular Biology deals with genetics')=='science'
  assert classify_text('Basketball is a popular sport')=='sports'
  assert classify_text('Physics is the study of matter')=='science'
output: def classify_text(text):
      sports_keywords = {'football', 'basketball', 'soccer', 'cricket', 'team', 'sport'}
      science_keywords = {'biology', 'genetics', 'physics', 'chemistry', 'study', 'matter', 'molecular'}
      
      words = set(text.lower().split())
      
      sports_count = len(words & sports_keywords)
      science_count = len(words & science_keywords)
      
      if sports_count > science_count:
          return 'sports'
      elif science_count > sports_count:
          return 'science'
      else:
          return 'science'  # default to science if counts are equal or no keywords are found