【正确答案】Besides making the city beautiful, the professor discusses two ways in which planting trees is beneficial to the city.
Probably the main advantage is that trees help remove carbon dioxide from the air.
The gas emissions produced by cars in cities are a major cause of the greenhouse effect and air pollution. The more trees there are, the more fresh air there is to breathe.
Another benefit is that trees store water and then let it evaporate slowly into the air. In this way, the air isn't so dry and our environment is more comfortable.
【答案解析】[听力原文]
W: Why bother planting trees downtown? I mean city is city, country is country and you're not going to make this city beautiful with just a tree or two hundred. Actually, there are two benefits of planting trees in the city other than beauty.
Consider the number of cars here. The air is actually unhealthy to breathe. Among other things, cars emit carbon dioxide, C02. If C02 is high, that means less oxygen for you and I to breathe. It's also a major cause of global warming, you know, the greenhouse effect. Well, good news is that trees help remove carbon dioxide from the air. That's right, they reduce pollution just by being there.
Second, a problem with all these concrete sidewalks and paved roads is that the air is dry. As soon as water hits the hot pavements, it evaporates. More good news is that trees trap water and then slowly release it back into the air by what's called "transpiration." This means an increase in humidity and a more comfortable living environment. So remember, trees in urban areas can improve our life.
Alternative Wording(替换表达)
Synonyms (a)remove—filter out (b)major cause of—major factor in
(c)environment—setting
Paraphrases 1. Carbon dioxide has been identified as the major culprit in global warming, especially as produced by cars that proliferate in urban settings./That gas is a major cause of the greenhouse effect and is produced, in large part, by the very cars that damage the urban environments.
2. The more the trees, the more the oxygen.