听下面的对话，回答1小题。
1.What does Mary want to be in the future?
A.A basketball player. B.A famous football player. C.A singer.
听第二段对话，回答第2小题。
2.What was John two years ago?
A.A bank clerk. B.A waiter. C.An ofice worker.
听第三段对话，回答第3小题。
3.What do they think there will be in 100 years?
A.More pollution and less water.
B.Less pollution and more water.
C.More pollution and more water.
