input: Write a python function to remove duplicate strings from a list while preserving the order.
  assert remove_duplicates(["AB", "AC", "AB", "CD", "AC"]) == ["AB", "AC", "CD"]
  assert remove_duplicates(["A", "B", "A", "C", "B"]) == ["A", "B", "C"]
  assert remove_duplicates(["apple", "banana", "apple", "orange"]) == ["apple", "banana", "orange"]
output: def remove_duplicates(lst):
      seen = set()
      result = []
      for item in lst:
          if item not in seen:
              seen.add(item)
              result.append(item)
      return result