input: 
  def select_approved_rows(table_name: str, cur) -> list:
      """ Select all rows from a given table where the 'status' column is 'approved'.
      >>> select_approved_rows('orders', cur)
      [('1', 'John Doe', 'approved'), ('3', 'Jane Smith', 'approved')]
      >>> select_approved_rows('requests', cur)
      []
      """
      sql = f"SELECT * FROM {table_name} WHERE status = 'approved'"
      cur.execute(sql)
      return cur.fetchall()
  
output:     sql = f"SELECT * FROM {table_name} WHERE status = 'approved'"
      cur.execute(sql)
      return cur.fetchall()