Yang Lei now works as a math teacher at a high school in a city. Last year she went to a poor mountain village as a 11  __ to teach the students .though life there was very difficult, she said she 12  __the students. Because the students always study hard. She also said she  13___  return to the area 14 ____ finishing her studies. That was an unusual _15______ for her.

(   )16.  Last Sunday, an old lady went shopping.

(   )17.  The man got out of a car and went into a bank.

(   )18.  The old lady saw a lot of money in the car.

(   )19.  The old lady was foolish.

(   )20.  The man ran out of the bank without any money.