Listen to part of a lecture in an environmental science class. The professor is discussing the role of wetlands in flood control.
"Now, we often think of wetlands as wastelands, but they provide crucial ecosystem services. One key function is flood mitigation. When rivers overflow, wetlands act like natural sponges, absorbing excess water and slowly releasing it over time. This reduces the peak flow downstream, which can prevent catastrophic flooding in urban areas. For example, the Mississippi River basin historically had vast wetlands that absorbed floodwaters. After many were drained for agriculture, major floods in 1993 and 2011 caused billions of dollars in damage. However, restoring even a fraction of these wetlands can make a significant difference. A study in the Midwest found that restoring 10% of wetland area in a watershed could reduce flood peaks by up to 20%. Additionally, wetlands filter pollutants and provide habitat for wildlife. So, while they might seem unproductive, they are actually cost-effective infrastructure for climate resilience."
❓ คำถาม What is the main point the professor makes about wetlands?
A. They are unproductive and should be converted to farmland.
B. They are highly effective in reducing flood risks and provide other benefits.
C. They are too expensive to restore compared to man-made flood barriers.
D. They only help with flood control in the Midwest region.
✅ คำตอบที่ถูกต้อง
They are highly effective in reducing flood risks and provide other benefits.
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
