input: Write a function to sort a list of numbers in ascending order.
  assert sort_ascending([4, 2, 9, 1, 5, 6]) == [1, 2, 4, 5, 6, 9]
  assert sort_ascending([10, 7, 8, 3, 2, 1]) == [1, 2, 3, 7, 8, 10]
  assert sort_ascending([5, 3, 4, 2, 1]) == [1, 2, 3, 4, 5]
output: def sort_ascending(numbers):
      return sorted(numbers)