A、It was a custom to do so. B、There was flu in the city. C、The pollution was serious. D、Wearing a mask was popular. C女士说这个城市的空气质

W: The air quality in this city is awful![9]The pollution levels were so high that we weren’t supposed to go outside without a face mask again.
M: Exhaust from vehicles causes a great deal of damage to the environment.
W:[10]On top of that, there are a few large chemical factories in the suburbs, which are contributing to the high pollution levels in the water and the air in this city.
M: Much as I love this city, I think I’m going to have to find a greener city to live in. Living in a polluted city like this just can’t be good for my health.
W: I know what you mean. However, there are so few places left that have not been affected by global wanning. If it’s not the pollution, then it’s the natural disasters or the greenhouse effect.
M: What is the greenhouse effect exactly?
W: It’s the gradual rise in the earth’s temperature.
M: I see, so it’s similar to global warming?
W: Yes, they’re related to each other.
M: I heard that some people in England are pleased with the fact that the climate is becoming warmer because it’s making their towns a more pleasant place to live.
W: People joke about the benefits of the increase in temperature, but it’s not all good news. They’ve been experiencing a lot of deadly storms there as well.
M: People always seem to make jokes as a way to deal with unfortunate situations.
W: I think if everyone pitches in, the world will be a better place.
9. Why were people supposed to go out with face masks?
10. What is the top reason for the serious pollution in the water and the air?
11. Why do some Englishmen like warmer weather?