听一段材料，回答下面几个小题。
What did the boy mean by saying "Mary, how did you do that"?
A. How Mary went on the holiday.
B. Why Mary went to Denver.
C. How Mary was able to miss so much school.
What can we infer about Washington's Birthday from the dialogue?
A. May be there was a national holiday near that day.
B. It was fine that day and nobody wanted to stay in.
C. All the students were on their winter holiday that day.
What did Mary do on Washington's Birthday?
A. She stayed at home.
B. She went to the mountain by car.
C. She went to the mountain by train for a holiday.