input: Write a function to select all rows from a table where the 'status' is 'approved'. If the table is empty or no rows have the 'status' of 'approved', the function should return an empty list.
  
  assert select_approved_rows()==[]
  assert select_approved_rows()==[('John', 'approved'), ('Jane', 'approved')]
  assert select_approved_rows()==[]
  assert select_approved_rows()==[('Jack', 'approved')]
  assert select_approved_rows()==[]
output: def select_approved_rows():
      table = [('John', 'approved'), ('Jane', 'approved'), ('Jack', 'pending')]
      return [row for row in table if row[1] == 'approved']