托福听力Lecture 2文本题目及答案解析_易伯华托福培训机构

托福培训机构,托福保分班,北京托福培训,托福课程,易伯华教育

作为托福考生必备托福提分备考工具，和TPO模考软件相爱相杀的日子终生难忘。作为整个托福考试的重中之重，托福听力对于托福er们非常重要，那么应该如何利用现有的TPO模考软件来提升托福成绩呢?易伯华托福频道为大家整理了TPO52托福听力Lecture 2资料，包含听力原文，题目及参考答案。来了解一下。

TPO52托福听力Lecture 2原文文本

标题：Interactions within an Ecosystem

Listen to part of a lecture in an environmental science class.

Professor:

Today we are going to begin discussing ecosystems. One important point I want to emphasize in the reading is that there are many interactions that take place within an ecosystem, interactions between animals, interactions between living and non-living things and so on. Now these interactions can be fairly simple and straight forward straightforward.

Ah, there are certain species of ants and rodents sharing a desert ecosystem in Arizona. And they compete for the same plants to eat. And the competition influenced not only the size of the ant and rodent populations, but also the number of eventual plants. Now, this interaction is easy to see, right? However, there are many other interactions within ecosystems that are not so apparent and require closer examination. And the example from your reading was the forest ecosystem along the specificPacific coast of North America. Um,specificallythe role of salmon.

Ok, as you probably know, salmon are born in fresh water streams, they might ran to oceans where they spent most of their lives. And then they return to the same streams where they were born to reproduce, or spawn. In order to spawn, salmon need cold, clear streams to ensure the survival of their eggs. And trees in the surrounding forest play an important role here. Their leaves provide shade from the Sun. When logging removes the trees, the streams are open to the Sun and the water becomes warmer. When the water warms up, the concentration of dissolved oxygen in the water decreases. And this reduces the chance that the salmon eggs were survived.

And the trees also help keep the soil on the banks of the stream in place. Salmon cannot spawn in streambeds clogged with sediment, dirt, from the surrounding area. They need a clean, grabble graveled streambed.

Bred?

Bred:I read that salmon also help keep stream healthy.

Professor:

Right. Salmon contribute important nutrients like carbon and phosphorus. And these nutrients promote diversity in the stream environment. Ok, um, so salmon need trees to successfully reproduce, but surprisingly trees also need salmon. And bears play an important intermediary role. So in the autumn, bears are busy putting on extra-weight as they prepare to hibernate. Each bear catches an estimated 700 fish during the 45 days that the salmon are spawning.

The bears catch the salmon in the streams and then they carry them back into the forest to eat. Sometimes as much as 800 meters from the streams. And since the bears only eat about half of each fish they catch, other animals like eagles, crows and insects feed on the leftovers.

Maria?

Maria:Why did the bears bring the salmons so far into the forest? Why not just eat the fish near the streams?

Professor:

Well, imagine several hungry bears looking for salmon. When one bear catches a fish, it’s not uncommon for another bear to try stealing it. These confrontations can be pretty intense. So it’s safer to bring it back into the forest, to a place where the bear can eat undisturbed.

Bred:

Um, you said that the bears only eat half of each fish they catch? I mean if I were a bear preparing to hibernate, I probably eat everything I can catch.

Professor:Well, certain parts of a salmon are more nourishing, fattier than others. It’s actually moreefficientfor a bear to only eat some parts of the fish and then try catching another one, instead of eating the whole fish.

Ok. So after the scavengers have eaten the leftovers, only the fish’s skeleton remains. Now, salmon contain nitrogen. So their decomposing bodies as skeletons provide a lot of nitrogen to the surrounding forest. Plants absorb this nitrogen which they need to grow. So the transfer of this nitrogen to the forest is important. Forest near streams with salmon actually reach maturity faster than other forests.

Ok, so, why’s all these important? Well, salmon are in trouble. Some of their populations have gone extinct. And most of the remaining populations have been significantly reduced by overfishing and environmental challenges. Now, conservationists can try to prevent overfishing but, well, I mean you can see the interconnections within this ecosystem. We’ve already talked about the importance of trees to salmon and the negative effect that something like logging can have. So you can see that protecting this ecosystem is going to take a broad effort.

TPO52托福听力Lecture 2题目

12. What is the main purpose of the lecture?

To familiarize students with the Mayan civilization in the Classic Period

To prepare students for an archaeology project about the Mayan civilization

To provide evidence for a point made in a previous class about the Mayan civilization

To call into question a common view about the decline of ancient Mayan civilization

13. Why does the professor discuss Lamanai in detail?

To present findings about one Mayan settlement from the Postclassic period

To describe the physical layout of the first Mayan settlements in Central America

To criticize the excavation methods used there during the 1970s

To note how the size of a typical Mayan settlement varied throughout its history

14. What is one of the features that gives Lamanai special archaeological significance?

It was the first Mayan site in Belize to be excavated in modern times.

It was occupied by two distinct cultural groups during the Classic period.

It was continuously occupied by the Maya longer than any other site.

It had an economic structure that was distinct from that of other Mayan cities.

15. Why does the professor say that it would require ;lots of funding; to uncover the stone structures that she discusses?

Because there are so many of them

Because very few archaeologists are given access to them

Because they are located on so many different islands

Because of difficult weather conditions in the region

16. According to the professor, what can be inferred from the ceramic artifacts found on the island?

The island was the source of most of the pottery used at Lamanai.

Much of Lamanai's population relocated to the island during the Postclassic period.

The Mayan trading network remained strong during the Postclassic period.

The Maya developed new technological capabilities on the island.

重听题：17.Why does the student say this:

To request that the professor repeat the point she just made

To express his doubt about the period of time being discussed

To disagree with the professor's interpretation of the evidence about Lamanai

To find out if he correctly understands the professor's point

TPO52托福听力Lecture 2答案解析

12.答案：C

解析：此题出处是：

However, there are many other interactions within ecosystems that are not so apparent and require closer examination. And the example from your reading was the forest ecosystem along the pacific specific coast of North America. Um, specifically the role of salmon.

这里教授在用蚂蚁和啮齿动物的例子简单说明生态系统里的相互作用之后，开始讲课本里提到的复杂的相互作用，即北美森林里关于大马哈鱼、树木和熊的相互联系，整个讲座片段主要就是讲这个生态系统里的相互作用的，选项C合适。选项A是确保森林生态系统存活的新办法，选项B是沙漠和森林生态系统的相似之处，选项D是森林系统中保护大马哈鱼的因素，都不合适。选择C。

13.答案：D

解析：此题出处是：

Ah, there are certain species of ants and rodents sharing a desert ecosystem in Arizona. And they compete for the same plants to eat. And the competition influenced not only the size of the ant and rodent populations, but also the number of eventual plants. Now, this interaction is easy to see, right? However, there are many other interactions within ecosystems that are not so apparent and require closer examination.

教授提到蚂蚁和啮齿类动物的原因就是它们之间的互动比较简单，以解释下生态系统中的互动这个概念。选项D合适。选项A是为了确保学生理解生态系统的组成成分，选项B是为了指出沙漠系统有机体可以获得的有限资源，选项C是为了解释不同的物种是怎么适应极端环境的，都不合适。选择D。

14.答案：BD

解析：此题出处是：

In order to spawn, salmon need cold, clear streams to ensure the survival of their eggs. And trees in the surrounding forest play an important role here. Their leaves provide shade from the Sun.

And the trees also help keep the soil on the banks of the stream in place. Salmon cannot spawn in streambeds clogged with sediment, dirt, from the surrounding area. They need a clean, grabble graveled streambed.

教授在这里提到了树木对于大马哈鱼产卵的两处好处：一是可以遮挡照射溪水的阳光，让溪水保持凉爽;二是可以保持水土，让溪水干净清澈。选项B和选项D分别符合这两点。选项A是说树木向溪水里提供大马哈鱼需要的营养，选项C是说它们帮助大马哈鱼提供应对捕食者的伪装，都不合适。双选BD。

15.答案：C

解析：此题出处是：

Ok. So after the scavengers have eaten the leftovers, only the fish’s skeleton remains. Now, salmon contain nitrogen. So their decomposing bodies as skeletons provide a lot of nitrogen to the surrounding forest. Plants absorb this nitrogen which they need to grow. So the transfer of this nitrogen to the forest is important. Forest near streams with salmon actually reach maturity faster than other forests.

这里教授提到，熊和其他生物吃剩下的大马哈鱼残渣会给树木提供氮元素，选项C合适。选项A说会导致熊吃的鱼变少，选项B说会导致食腐动物的食物减少，选项D说会使周围小溪的水质变好，都不合适。选择C。

16.答案：C

解析：此题出处是：

Now, conservationists can try to prevent overfishing but, well, I mean you can see the interconnections within this ecosystem. We’ve already talked about the importance of trees to salmon and the negative effect that something like logging can have. So you can see that protecting this ecosystem is going to take a broad effort.

这里教授指出，虽然说过度捕鱼是导致大马哈鱼陷入危机的原因之一，但是整个生态系统牵一发而动全身，所以如果真的想改善大马哈鱼的生存状况，还是要全面地进行努力，选项C合适。选项A说这是熊的数量减少的原因之一，选项B说很难去在海洋和溪水里一起阻止过度捕鱼，选项D说它的影响和伐木的影响比起来算是小的，都不合适。选择C。

17.答案：B

解析：此题出处是：

Bred:

Um, you said that the bears only eat half of each fish they catch? I mean if I were a bear preparing to hibernate, I probably eat everything I can catch.

这里学生对老师讲的熊只吃一半鱼提出疑问，他觉得如果是为冬眠储存脂肪的话，应该尽量多吃，把一整条鱼能吃的都吃了才对。选项B合适。选项A说是为了支持教授提出的假设，选项C说是为了解释为什么熊之间会起冲突，选项D说是为了解释为什么熊短时间内吃那么多东西，都不合适。选择B。