Listen to part of a lecture in an environmental science class. Professor: Today we're going to talk about a fascinating phenomenon known as bioluminescence, the ability of living organisms to produce light. While most of us think of fireflies, bioluminescence is actually far more common in the deep ocean. Over 90% of creatures living below 700 meters generate their own light. Why? Well, there are several purposes. Some species use it to attract prey, like the anglerfish, which dangles a glowing lure. Others use it for defense, such as squid that release a cloud of glowing particles to confuse predators. But perhaps the most intriguing use is for communication. For example, some shrimp produce light in specific patterns to signal mates or warn rivals. Interestingly, scientists have discovered that bioluminescence is not just a chemical reaction; it's highly efficient, converting nearly 100% of energy into light, unlike an incandescent bulb, which wastes most energy as heat. This efficiency has inspired research in medical imaging and sustainable lighting. So, next time you see a firefly, remember that it shares a deep ocean secret.
❓ 質問 What is the main purpose of the lecture?
A. A. To explain why fireflies are more common than deep-sea creatures
B. B. To describe the various functions of bioluminescence in marine life
C. C. To argue that bioluminescence is inefficient compared to human lighting
D. D. To discuss the chemical reactions that produce light in all organisms
✅ 正解
B. To describe the various functions of bioluminescence in marine life
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