Listen to part of a lecture in a biology class. Professor: Today we're going to talk about a fascinating example of animal adaptation: the wood frog. This small amphibian, found in North America, has an extraordinary ability to survive freezing temperatures. During winter, up to 65% of the water in its body can turn to ice. You might think that would kill it, but no. The frog's liver produces large amounts of glucose, which acts like a natural antifreeze. This glucose is distributed to vital organs, preventing ice crystals from forming inside the cells, which would cause damage. Meanwhile, the frog's heart stops beating, and it stops breathing. It appears frozen solid for weeks. But when spring arrives, the ice thaws, and the frog's heart and lungs resume functioning as if nothing happened. Researchers are studying this process because it could offer insights into human organ preservation for transplants. Imagine being able to freeze organs without damage—that would be a breakthrough.
❓ Вопрос What is the main purpose of the glucose produced by the wood frog?
A. A) To provide energy for the frog during hibernation.
B. B) To prevent ice crystals from forming inside the frog's cells.
C. C) To help the frog breathe when its heart stops.
D. D) To attract mates during the spring thaw.
✅ Правильный ответ
B) To prevent ice crystals from forming inside the frog's cells.
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