21. A, D
Peregrine falcons naturally prey on geese and ducks: …the right kind of bird can keep the wrong kind of bird away, so they started using peregrine falcons to patrol the runways; Mostly it was geese and ducks, because it’s near a wetland. But now, since they started the falcon program, and since falcons are predators, there haven’t been any bird-aircraft collisions that required any repairs! Peregrine falcons can fly faster than any other bird: They can exceed 200 miles per hour in a dive—faster than any other living creature. (2.2)
22. D
The student’s opinion is that the falcon program is interesting because it uses biology to solve a problem. She says The falcons get the credit for keeping the geese and ducks away. It’s an interesting solution to the problem, I mean, adding a predator to change the biology of the runway. (2.3)
23. B The professor mainly discusses how a market economy works. The professor says In this course, we ’ll look at the basic problems every economy must face. We ’ll focus on the modem industrial economy.We ’ll examine the market mechanism, how the problems of production are solved through a system of markets and prices. (2.1)
24. D
The professor’s purpose is to contrast a pure market economy with a mixed economy. First, the professor mentions the government’s important role in regulating business activity in a mixed economy. Then she states that a pure market system would have no government intervention, showing the contrast between the two systems. (2.3)
25. C The professor means that consumers use their money like votes to buys goods. The professor continues by saying They use their money…
26. B
The professor says The lower the price, the more they ’ll buy. So you can see there’s a definite relationship between the price of a good and the quantity demanded; But when the price falls, demand increases, as more people will be willing and able to buy it at a lower price. (2.2)
27. D
The professor implies that the supply of a good is directly related to its price. Businesses must make a profit, so when the price of a good is high, producers will supply more of it because they will make a higher profit. However, when the price is low, producers will supply a different, more profitable good. (2.4)
28. A
The professor says Tomorrow we ’ll look at just how supply and demand work in a real-world mixed economy. We ’ll see how the market price of a good is a function of supply and demand…. You can predict that the next lecture will be about examples of how supply and demand affect prices. (2.4)
29. C
The main idea of the talk is that fire revitalizes the forest and promotes a diversity of life. The instructor says Without fire, ecosystems can stagnate and lose their diversity of life; Now we know that fire is a natural agent that rejuvenates a forest. (2.1)
30. A
The instructor means that fire prevention has actually damaged the forest ecosystem. The previous forest policy was to eliminate forest fires. Preventing fires saved trees but at the expense of the forest community because periodic fires are natural and benefit the forest as a whole. (2.4)
31. A, C
Periodic fire is necessary to forest ecosystems because it releases nutrients into the soil. The instructor says Fire removes nutrients from standing dead trees and returns them to the earth, where they become available to the root systems of new trees. Fire also controls insect pests that harm trees. The instructor says Fire is nature s way of controlling insect infestations; …the heat kills off great numbers of beetles and larvae, providing a natural method of pest control. (2.2)
32. B
The instructor says The exclusion of fire from the ecosystem is creating unhealthy, overcrowded forests that contain more fuel for larger, more severe fires; …the flames were fed by dead wood and combustible debris that had accumulated on the forest floor over years of fire suppression. (2.2)
33. B
The instructor says Prescribed fire, or controlled fire…; …prescribed bums are carried out every three to five years in one of the national forests. These controlled burns…. (2.2)
34. D
The instructor’s purpose is to give examples of the negative effects of fire. The instructor says .. fire has consequences (negative effects), and then he lists smoky, hazy skies and patches of blackened forest, and the risk of a fire becoming too large as examples. (2.3)
35. C
The man needs help in improving his study skills. He says …I’m taking some difficult courses this semester and I have a lot of reading to do. I just feel like I need to bone up on my study skills, you know, learn how to study better. (2.3)
36. A
The woman suggests that the man attend one of the special workshops. She says You could take one of our special workshops. There are several of these each week. The workshops in study skills and time management are especially popular. (2.2)
37. B
The woman says We have several workshops. All of them are two hours long. Most are held in the evening, but there s a couple that are on the weekend. (2.2)
38. D
The man’s purpose is to express pleasure that the workshops are free. The woman says All of the workshops are free to students. The man replies Hey, that’s not a bad deal, meaning it is a good idea. (2.3)
39. B
The man is interested in taking a workshop in study skills. The woman says …there’s a sheet there for every workshop offered this semester, and that’s how you sign up. You can predict that the man will look at the workshops that are available. (2.4)
40. B
The professor mainly presents a comparison of two philosophers. The professor says …two of the world s great educational philosophers, Confucius and Dewey; …both of these thinkers held some interesting—and amazingly parallel—ideas about teaching and learning; As was the case with Confucius, some of Dewey s ideas were considered revolutionary; Despite the centuries that separated them, Confucius and Dewey held some similar ideas about knowledge, teaching, and learning. (2.1)