toeflprep3.mp3

What is the lecture mainly about?
1. How animals emit ultrasonic pulses
2. How bats use acoustical signals
3. A comparison of echolocation and radar
4. Variations among bats in the use of ultrasound
Why does the professor decide NOT to add more information to the diagram on the board?
1. She wants students to complete the diagram themselves as an assignment.
2. She needs to look up some information in order to complete the diagram accurately.
3. The additional information is not relevant to the topic that she wants to discuss next.
4. Students already have the additional information in their textbook.
according to the professor, what are two ways in which a moth might react when it detects the presence of a bat?
Choose 2 answers
.
1. The moth might stop beating its wings.
2. The moth might emit high-frequency sounds.
3. The moth might leave the area.
4. The moth might change its color to match its surroundings.
What surprising information did a recent experiment reveal about lesser spear-nosed bats?
1. They filter out echoes from some types of trees.
2. They can analyze echoes from stationary objects with complex surfaces.
3. They cannot analyze “jagged” echoes.
4. They cannot analyze echoes from certain types of small moving objects.
according to the professor, why does a pine tree produce a “smooth” echo?
1. Because it has a smooth trunk
2. Because it has large branches spaced at regular intervals
3. Because it has many small, densely packed needles
4. Because it remains stationary in all types of weather
Listen again
1. To answer a question that Carol asked
2. To correct a statement that Carol made
3. To praise Carol for an example that she gave
4. To give an example of a principle that Carol stated