Narrator: Listen to part of a lecture in an environmental science class. Professor: Today we're going to talk about a surprising factor in climate change: the role of forests. You might think that planting more trees is always good for the planet, but it's not that simple. Trees absorb carbon dioxide, yes, but they also release volatile organic compounds, or VOCs. These VOCs can react with nitrogen oxides in the atmosphere to form ozone and aerosols, which actually have a warming effect. In some regions, especially those with high pollution, the warming from these compounds can outweigh the cooling effect of carbon absorption. However, in pristine areas, forests are clearly beneficial. So, the net impact of forests on climate depends on local conditions. This means we need to be careful when designing reforestation projects—we should consider not just carbon, but also these complex chemical interactions.
❓ Pregunta What is the main point the professor makes about forests and climate?
A. Planting more trees always helps cool the climate because they absorb carbon dioxide.
B. Forests can have either a warming or cooling effect on climate depending on local conditions.
C. Forests release VOCs that always lead to ozone formation, which traps heat.
D. Reforestation projects should focus solely on maximizing carbon absorption.
✅ Respuesta correcta
Forests can have either a warming or cooling effect on climate depending on local conditions.
TOEFL Listening Tips
Skim the questions first to predict the content
Watch for signal words in lectures and conversations (however, actually, in fact)
For main idea questions, focus on the beginning; for detail questions, focus on examples and data
For attitude questions, pay attention to the speaker's tone and word choice
Take notes on keywords; don't try to write down every word