Narrator: Listen to part of a lecture in an environmental science class. Professor: So we've been talking about renewable energy sources, and today I want to focus on a lesser-known one: tidal power. Unlike solar or wind, tidal power is predictable because it's driven by the gravitational pull of the moon and the sun, which follows a regular cycle. However, it's not without challenges. Tidal energy requires a significant difference between high and low tide, typically at least five meters, to be economically viable. This limits it to specific coastal locations, like the Bay of Fundy in Canada or the Severn Estuary in the UK. Another issue is the environmental impact on marine ecosystems. The turbines used in tidal barrages can harm fish and disrupt sediment flow. But recent innovations, such as underwater turbines that don't require dams, may reduce these effects. So while tidal power has potential, its practical application remains niche.
❓ Question What is the professor's main point about tidal power?
A. It is a promising energy source that can be used everywhere in the world.
B. It has advantages over solar and wind power due to its predictability, but it also has limitations.
C. It is the most reliable renewable energy source and has no environmental drawbacks.
D. It is too expensive to develop and therefore should be abandoned.
✅ Correct Answer
It has advantages over solar and wind power due to its predictability, but it also has limitations.
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
