24- dictation
A: There are so many problems in the world today.
B: I know. There's water pollution, air pollution, global warming, unemployment.
A: Yeah, and there's the destruction of the rain forests, traffic problems, housing shortages... It can get depressing if you think about it too much.
B: No kidding. What do you think the biggest issues are?
A: I really think air pollution is the most important issue. If we don't reduce pollution and improve air quality, we'll all have health problems.
B: I agree that air pollution is a big problem. The air in the city has become so dirty.