81.今天天气很好，是吗？

　 82我已经当乘务员两年了。

83这道题太难了，我做不出来。

80. That’s the nicest stamp I ___________ (see) until now.

79. The box is too heavy. I’m not strong enough __________ (carry) it.

78. Could you please _________ (turn) down the TV?

77. You aren’t __________ (allow) to swim here.

76. The teacher came into the classroom while the students_________ (talk) loudly.

75. Would you mind __________ (close) the door?

74. They _____________ (skate) for 5 years.

73. We will go to the zoo if the rain __________ (stop).

72. She can make a living by__________ (draw) picture.