托福听力TPO7文本(Conversation+Lecture)

　　Lecture 3

　　Anthropology

　　The focus on Iroquois and Hooray peoples. They lived in the northeastern great lakes region of North America. Now, back then, their lives depended on the natural resources of the forests, especially the birch tree. The birch tree can grow in many different types of soils and it'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 ** things like cooking containers, a variety of utensils. And if you peel birch bark in the winter, we call it ‘the winter bark', another layer a tougher inner layer of the tree adheres to the bark, producing a stronger material. So the winter bark was used for larger utensils and containers.

　　Stu: I know people make utensils out of wood, but utensils out of tree bark?

　　Pro: Well, birch bark is pliable and very easy to bend. The Native Americans would cut the bark and fold it into any shape they needed, then secure with cords until it dried. They could fold the bark into many shapes.

　　Stu: So if they cooked in bowls made of birch bark, wouldn't that make the food taste funny?

　　Pro: Oh, that's one of the great things of birch bark. The taste of the birch tree doesn'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 over-grown, so water travel was much faster. And here's what the Native Americans did. They would peel large sheets of bark from the tree to form light-weight yet sturdy canoes. The bark was stretched over frames made from tree branches, stitched together and sealed with resin. You know that sticky liquid that comes out of the tree? And when it dries, it'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 could they drive that way?

　　Pro: Well like I said, the northeastern region is interconnected by rivers and streams and the ocean at the coast. The canoes allow them to travel over a vast area that today it would take a few hours to fly over. You see, the Native Americans made canoes of all types, for travel on small streams or on large open ocean waters. For small streams, they made narrow, maneuverable boats, while a large canoe was needed for the ocean. They could travel throughout the area only occasionally having to portage, to carry the canoe over a land short distance to another nearby stream. And since the canoes were so light, this wasn't a difficult task. Now how do you think this affected their lives?

　　Stu: Well if they could travel so easily over such a large area, they could trade with people from other areas which I guess would lead them to form alliances?

　　Pro: Exactly. Having an efficient means of transportation, well, that helps the Iroquois to form a federation linked by natural waterways. And this federation expanded from what is now Southern Canada all the way south to the Dalever River. And this efficiency of birch bark canoe also made an impression on newcomers of the area. French traders in the 17 century modeled their...well they adopted the design of Yreka’s birch bark canoes, and they found they could travel great distances more than 15 kilometers a month. Now besides the bark, Native Americans also used the wood of the birch tree. The young trees were used to support for loggings with the waterproof bark used as roofing. Branches were folded into snow shoes and the Native American people were all adept to running very fast over the snow in these birch brand snow shoes which if you ever tried walking in snow shoes you know wasn't easy.