Listen to part of a lecture in an environmental science class. Professor: Today we're going to talk about a fascinating adaptation in desert plants, specifically the saguaro cactus. The saguaro, native to the Sonoran Desert, can live over 150 years and grow to be 40 feet tall. But what really interests scientists is its root system. Unlike many plants that spread roots deep into the soil, the saguaro has a shallow, widespread root system that extends horizontally, often as far as the plant is tall. These roots are only a few inches below the surface, which allows them to quickly absorb moisture from infrequent rains. The roots also have a special relationship with certain fungi, which help the cactus absorb nutrients more efficiently. Additionally, the saguaro's stem has accordion-like folds that expand to store water after a rain, enabling it to survive long dry periods. This combination of shallow roots and water storage is a remarkable example of adaptation to extreme conditions.
❓ Câu hỏi What is the main point of the lecture?
A. A. The saguaro cactus can live for over 150 years.
B. B. The saguaro cactus has a unique root system and water storage mechanism.
C. C. The Sonoran Desert has very little rainfall.
D. D. Fungi are harmful to the saguaro cactus.
✅ Đáp án đúng
B. The saguaro cactus has a unique root system and water storage mechanism.
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
