Listen to part of a lecture in a biology class. The professor is discussing animal communication.
Professor: Today we're going to talk about a fascinating aspect of animal behavior: communication. While many animals use sounds or visual signals, some have developed incredibly sophisticated chemical communication. For example, ants release pheromones to mark trails, warn of danger, or even identify nestmates. But perhaps the most striking example is found in certain species of moths. Female moths emit a single chemical compound that can attract males from miles away. The male's antennae are so sensitive that they can detect just a few molecules of this substance. Interestingly, recent research shows that some predators, like certain spiders, exploit this system. They mimic the female moth's pheromone to lure males into their web. This is a clever adaptation, but it also raises questions about the evolutionary arms race between signalers and receivers. The signal must be specific enough to avoid confusion with other species, yet strong enough to be detected, which creates a delicate balance. So, as you can see, chemical communication is not just about sending a message; it's about survival and deception.
❓ 문제 What is the main point the professor makes about chemical communication in animals?
A. It is less common than visual communication.
B. It involves a balance between specificity and detectability.
C. It is primarily used by insects to mark territories.
D. It has been completely understood through recent research.
✅ 정답
It involves a balance between specificity and detectability.
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