text: #练习4-10
  pizzas = ['chicken pizza','onion pizza','beef pizza','durian pizza','mongo pizza','vegetable pizza']
  print('The first three items in the list are:')
  print(pizzas[0:3])
  
  print('\nThree items from the middle of the list are:')
  print(pizzas[2:4])
  
  print('The last three items in the list are:')
  print(pizzas[-3:])
  
  #练习4-11
  friend_pizzas = pizzas[:]
  pizzas.append('turkey pizza')
  friend_pizzas.append('sausage pizza')
  print('my favorite pizzas are:')
  for pizza in pizzas:
      print(pizza)
  print("\nMy friend's favorite pizzas are:")
  for friend_pizza in friend_pizzas:
      print(friend_pizza) 
  
  #练习4-12
  #就这？
  
  #练习4-13
  pizzas = ('chicken pizza','onion pizza','beef pizza','durian pizza','mongo pizza','vegetable pizza')
  for pizza in pizzas:
      print(pizza)
  
  # pizzas[0] = 'shit pizza'
  
  pizzas = ('chicken pizza','fish pizza','seastyle pizza','durian pizza','mongo pizza','vegetable pizza')
  for pizza in pizzas:
      print(pizza)