NARRATOR:Listen to part of a lecture in an anthropology class.
FEMALE PROFESSOR:So we've been discussing 16th century native American life and today we're gonna focus on the Iroquois and Huron peoples, um they lived in the northeastern Great Lakes region of North America.Now, back then, their lives depended on the natural resourses of the forests especially the birch tree.The birch tree can grow in many different types of soils and is prevalent in that area.Now can anyone here describe the birch tree.
MALE STUDENT:Umm, they’re tall? And…white? The bark, I mean.
FEMALE PROFESSOR:Yes, the birch tree has white bark and this tough protective out layer of the tree is white bark, is waterproof.And this waterproof quality of the bark, always made it useful for making things like cooking containers and 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
MALE STUDENT:Um,I know people make utensils out of wood, but…[skeptical] utensils out of the tree bark.
FEMALE PROFESSOR: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.
FEMALE STUDENT:So if they cooked in bowls made of birch bark, wouldn't that make the food taste funny?
FEMALE PROFESSOR:Oh that's one of the great things about 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 northeast region of the north American is interconnected by many streams and water ways, water transportation by vessels like canoe was most essential.The paths through the woods were often over-grown so water travel was much faster.And here is what the native Americans did…they would peel large sheets of the bark from the trees 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 the sticky liquid that comes out of the tree—and when it dries, it's watertight.
One great thing about this birch bark canoe was they could carry a large amount of cargo.For example, a canoe weighing about 50 pounds could carry up to 9 people and 250 pounds of cargo.
FEMALE STUDENT:Wow, but how far could they travel that way?
FEMALE PROFESSOR:Well, like I said, the northeastern region is interconnected by rivers and streams and the ocean at the coast.The canoes allowed them to travel over a vast area that today we take a few hours to fly over.You see, the native Americans made canoes of all types, for travelling on small streams or on large open ocean waters.For small streams they made narrow, maneuverable boats, while, while larger canoes were needed for the ocean.They could travel throughout the area, only occasionally having to portage, to carry the canoe over land of 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?
FEMALE STUDENT: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.
FEMALE PROFESSOR:Exactly, having an efficient means of transportation, well that helped the iroquois to form a federation, linked by natual water ways.And this federation expanded from what's now southern Canada all the way south to Delaware River.And this efficiency of the birch bark canoe also made an impression on the newcomer to the area.French traders in the 17th century modeled their... well, they adopted the design of the Iroquois birch bark canoes and they found they could travel great distances—more than 1500 kilometers a month.
Now besides the bark, native Americans also use the wood of the birch tree. Eh, the young trees were used to support for loggings, with the waterproof bark used as roofing.Um branches were folded into snowshoes, and the native American people were all adept at [chuckle] running very fast over the snow in these birch branch snowshoes which if you've ever tried to walk in the snowshoes, you know it wasn't easy.
Now, uh back then, eh their lives depended on the
natural resources of the forest, especially the birch tree.
教授在开始说人们的生活依靠森林提供的资源，尤其是birch tree，之后的文章都在讲birch tree的用处，对应答案C。A选项，different kinds of trees未提及。B选项，Various methods of transportation未提及，只说了canoe。D选项， trading of birth wood是细节。