input: Write a function to remove elements of the second list from the first list.
  assert remove_elements([1, 2, 3, 4, 5], [3, 4]) == [1, 2, 5]
  assert remove_elements([10, 20, 30, 40], [20, 30]) == [10, 40]
  assert remove_elements([5, 6, 7, 8], [6, 8]) == [5, 7]
output: def remove_elements(list1, list2):
      return [item for item in list1 if item not in list2]