Listen to part of a lecture in an environmental science class. The professor is discussing the role of wetlands in flood control.
"Now, many of you might think of wetlands as just muddy, mosquito-infested areas, but they actually provide crucial ecosystem services. One of the most important is flood mitigation. Wetlands act like natural sponges. They absorb excess rainwater and slowly release it over time, which reduces the peak flow of rivers and streams during heavy storms. For example, in the Mississippi River basin, studies have shown that restoring just a fraction of the original wetlands could significantly lower flood levels in downstream cities. However, over the past century, about half of the world's wetlands have been drained or filled for agriculture and urban development. This loss has made many areas more vulnerable to flooding. So, some governments are now investing in wetland restoration as a cost-effective alternative to building concrete levees and dams. But there's a catch: wetlands need space and time to function properly, and they cannot be created overnight. It takes years for the vegetation and soil to develop the capacity to store water effectively."
❓ Вопрос What is the main point the professor makes about wetlands?
A. A. Wetlands are harmful because they attract mosquitoes and cause disease.
B. B. Wetlands are valuable for flood control, but their loss has increased flood risks, and restoration takes time.
C. C. Building levees and dams is more effective than restoring wetlands.
D. D. Wetlands are only useful in the Mississippi River basin.
✅ Правильный ответ
B. Wetlands are valuable for flood control, but their loss has increased flood risks, and restoration takes time.
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