【正文】 re of what the Chanson hero was like. Now let39。s a...he39。s admired for his courage, bravery and loyalty, loyalty to the lord he serves, his country and his fellow warriors in the field. He39。s still contested somewhat, but we are pretty sure about who the Chanson poems were written for. That is, they were written for knights and the lords, the nobility that they served. The poems were sung, performed by a minstrel, a singer who travelled from castle to castle, singing to the local lord and his knights. Ah... well...um... would someone summarize the main features of the Chanson poem you read? Male student Well, there39。s Chanson. Chanson poems became popular in Europe, particularly in France, and the term is actually short for a longer French phrase that translates to um... songs of deeds. Now they were called songs of deeds because strangely enough, they were written to describe the heroic deeds or actions of warriors, the knights during conflicts. We don39。s written to evoke, to make you, the audience, have some kind of emotional experience through the use of imagery, um, some kind of predictable rhythm. And usually, but not always, there39。s right Female student But, professor, are you sure these are poems? I mean I thought poems were shorter. These are more like long stories. I mean one of them was all about love, but the other one, the Chen...Chan...Chan...whatever it39。s probably already started watching it... Manager No problem. We39。t really understand. Student I guess I prefer my own room. I concentrate better by myself and I don39。s half an hour long. Student So, it’s a video library, basically? Manager Yes, but unlike the library, you can39。t been here before. Student No, no I haven39。m taking first year Spanish this semester. Our professor says we need to e here to view a series of videos. I think it39。ve probably heard about water shortages or restrictions on how much water you can use, especially in the summer time in recent years. And remember what I said about groundwater. Imagine if we still had all those beavers around, all those wetlands, what would our water supply be like then? Section 2 Conversation 2 已整理 Narrator Listen to a conversation between a student and the language lab manager. Student Hi! I39。s the crucial species that keeps the system going. Now beaver populations are on the rise again, but there39。t support as many species because a lot of insects and fish and frogs can’t live in running water, and then the birds and animals that eat them lose their food supply. Professor Precisely. So the beaver in this ecosystem is what we call a keystone species. The term keystone kind of explains itself. In architecture a keystone in an archway or doorway is the stone that holds the whole thing together and keeps it from collapsing. Well, that39。s go back to where you were headed before, Mike, you mentioned a change that occurred after Europeans came to North America. Mike Yeah, well, there used to be beavers all over the place, um, something like 200 million beavers, just in the continental United States. But when Europeans came, they started hunting the beavers for their fur 39。t there? Mike You just have a regular running stream 39。s something about wetlands and ground water too. Professor OK, good! Wetlands have a big effect on groundwater, the amount of water below the surface of the land. Think of wetlands as, um, like a giant sponge. The earth soaks up a lot of this water that39。s a lot cleaner than swiftly flowing water because the dirt and sediment and stuff has a chance to sink to the bottom. Professor More important for our discussion: wetland areas support a lot more varieties of life than swiftly flowing water. For example there are more varieties of fish, of insects, lots of frog species, and then species that rely on those species start to live near the wetlands, too. Kate Yes, like birds and mammals that eat the fish and insects. And you get trees and plants that begin to grow near the standing water that can39。s like there39。s so important, 39。t until a convention center and a parking garage were built about a decade later that the mall started to be successful. Lecture 2 已整理 Narrator Listen to part of a lecture in an ecology class. Professor So, um, continuing our discussion of ecological systems, whole systems, the main thing to keep in mind here is the interrelationships. The species in a system and even the landscape itself, they are interdependent. Let39。d be the first to admit those things are aesthetically appealing. However, visually pleasing sights...well they are not a part of the pedestrian mall design that matter the most. The key consideration is a pact and convenient layout, one which allows pedestrians to walk from one end of the mall to the other in just a few minutes, so they can get to the major stores, restaurants and other central places without having to take more than one or two turns. Now, this takes careful and creative planning. But now what if one ingredient to this planning recipe is missing? There could quite possibly be longlasting effects. And I think a good example is the pedestrian mall in Louisville Kentucky for instance. Now, when the Louisville mall was built, it had lots of visual appeal. It was attractively designed, right in the small part of downtown and it pretty much possessed all of the other design elements for success. But, now here is where my point about location es into play, there wasn39。s location, but what about design? Well, design doesn39。s where access to public transportation es in. Either...um...either the designers plan to locate the mall near a central transportation hub, like a bus terminal, a major train or subway station, or they work with city officials to create sufficient parking areas