【正文】 ents known as the: An obligatory scene. It?s scene, a moment in which all the secrets are reviewed. In generally, things turn out well for the hero and others we are care about, a happy ending of some sorts. This became so popular that the playwright almost had to include it in every play which is why is called: the obligatory scene. And that?s followed by the final dramatic elementthe denouement or the resolution, when all the lucent have to be tight up in the logical way. Remember, the obligatory scene gives the audience emotional pleasure. But the denouement offers the audience a logical conclusion. That?s the subtle distinction we need to try very hard to keep in mind. So, as I said, the wellmade play, this form of playwriting, became the base for realism in drama, and for a lot of very popular 19 century plays. And also, a pattern we find in plots of later many play, and even movies that we see it today. Lecture Pro: So, that is how elephant uses infrasound . Now, let?s talk about the other and the acoustic spectrums, sound that is too high for humans to hear ultrasound s. Ultrasound is used by many animals that detected and some of them seen out very high frequency sounds. So, what is a good example? Yes, Kayo. Kayo: Well, bats, since there is all blind, bets have to use sound for, you know, to keep them from flying in the things. Pro: That is echolocation. Echolocation is pretty selfexplanatory 。 it has diagram shows this very clearly. So, anyway, as I were saying, by analyzing this echo, the bat can determine, say, if there is wall in a cave that needs to avoid, and how far away it is. Another thing uses the ultrasound to detect is the size and the shape of objects. For example, one echo they quickly identified is one way associated with moth, which is mon prey for a bat, particularly a moth meeting its wings. However, moth happened to have major advantage over most other insects. They can detect ultrasound。t e to our student orientation and I39。s your major area of study? Stu: Latin American Literature. Pro: OK. Well, over here39。ve already done a year in another university so I know how the research can go that spent a lot of time on history section. So how long can I borrow books for? Pro: Our loan period is a month. Oh I should also mention that we have an interlibrary loan service. If you need to get to hold a book that not in our library, there is a truck that runs between our library and a few public and university libraries in this area. It es around three times a week. Stu: It39。s the idea. I am sure you39。ll need to buy a card from the front desk. You would insert it into the machine and you read it into the copies. Stu: How much do you get charge? Pro: Seven cents a copy. Stu: Hum, that is not too bad. Thanks. Hum, where is the collection of the rare books? Pro: Rare books are upon the second floor. There is in the separate room where the temperature controlled, to preserved old paper in them. You need to get special permission to access, and then you have to need to wear gloves to handle them because the oil in our hands, you know, can destroy the paper. And gloves prevent that so we have a basket of gloves in the room. Stu: Ok. Thanks. I suppose that all I need to know. You39。ve been discussing 16th century Native American life, and today we39。s prevalent in that area. Now can anyone here describe the birch tree? Stu: They are tall and white, the bark, I mean. Pro: Yes. The birch tree has white bark, and this tough protective outer layer of the tree, this white bark, is waterproof. And this waterproof quality of the bark, it made it useful for making things like cooking containers, a variety of utensils. And if you peel birch bark in the winter, we call it ?the winter bark39。t that make the food taste funny? Pro: Oh, that39。t get transferred to the food. So it was perfect for cooking containers. But the most important use of the bark, by far, was the canoe. Since the northeastern region of North American is interconnected by many streams and waterways, water transportation by vessels like a canoe was most essential. The paths through the woods were often overgrown, so water travel was much faster. And here39。s watertight. One great thing of these birch bark canoes was that they could carry a large amount of cargo. For example, a canoe weighing about 50 pounds could carry up to nine people and 250 pounds of cargo. Stu: Wow! But how far