input: Write a python function to sort a list of words and their scores in descending order of scores.
  assert sort_list([("cat", 5), ("dog", 2), ("elephant", 7), ("tiger", 3)]) == [("elephant", 7), ("cat", 5), ("tiger", 3), ("dog", 2)]
  assert sort_list([("apple", 10), ("banana", 15), ("cherry", 7)]) == [("banana", 15), ("apple", 10), ("cherry", 7)]
  assert sort_list([("one", 1), ("two", 2), ("three", 3), ("four", 4)]) == [("four", 4), ("three", 3), ("two", 2), ("one", 1)]
output: def sort_list(words_scores):
      return sorted(words_scores, key=lambda x: x[1], reverse=True)