托福听力

🎧 听力原文

Listen to part of a lecture in an environmental science class. The professor is discussing the role of wetlands in flood control. "Now, many people think of wetlands as useless, swampy areas that should be drained for development. But in fact, wetlands play a crucial role in flood prevention. They act like natural sponges. When heavy rain occurs, wetlands absorb and store large amounts of water, slowly releasing it over time. This reduces the peak flow of rivers and streams, which can prevent downstream flooding. In contrast, when wetlands are destroyed, water runs off quickly into rivers, causing sudden and severe floods. For example, along the Mississippi River, the loss of wetlands has contributed to more frequent and intense flooding events in recent decades. Restoring these areas, however, is not always easy. It requires significant land and financial resources, and it may conflict with agricultural or urban interests. Still, many experts argue that investing in wetland restoration is cost-effective compared to the damage costs of major floods. So, the next time you see a marsh, remember it's not just a mosquito habitat—it's a vital part of our flood defense system."