【小站原创】官方真题Official10托福听力Lecture1文本+真题+答案解析
- 2018年01月31日18:03 来源：小站整理
- 参与（0） 阅读（74585）
现在大家在进行托福备考时官方真题Official托福模考软件相信是大家用的最多的工具了，对于托福成绩的提升是非常有帮助的。托福听力可以说是整个托福考试当中比较重要的一个部分，如何利用现有资料官方真题Official模考软件来提升大家的托福成绩呢?今天小编在这里整理了官方真题Official10托福听力Lecture1文本+题目+答案解析来分享给大家，希望对大家托福听力备考有帮助。
官方真题Official10托福听力Lecture1原文文本
Narrator: Listen to part of a lecture in a Marine Biology Class.
Professor: We know whales are mammals and that they evolved from land creatures. So the mystery is figuring out how they became ocean dwellers. Because until recently there was no fossilrecord of what we call “the missing link” – that is evidence of species that show the transition between land-dwelling mammals and today’s whales. Fortunately, some recent fossil discoveries have made the picture a little bit clearer.
For example, a few years back in Pakistan, they found the skull of a wolf-like creature. It was about 50 million years old. Scientists had seen this wolf-like creature before, but this skull was different. The ear area of the skull had characteristics seen only in aquatic mammals, specifically whales.Uh, well, then also in Pakistan, they found a fossil of another creature, which we call Ambulocetus Natans.
That’s a mouthful, eh? The name Ambulocetus natans comes from Latin of course, and means “walking whale that swims”. It clearly had four limbs that could have been used for walking. It also had a long thin tail, typical of mammals, something we don’t see in today’s whales. But, it also had a long skeletal structure. And that long skeletal structure suggests that it was aquatic.
And very recently in Egypt, they found a skeleton of Basilosaurus. Basilosaurus was a creature that we had already known about for over a hundred years. And it has been linked to modern whales because of its long whale-like body. But this new fossil find showed a full set of leg bones, something we didn’t have before.
The legs were too small to be useful. They weren’t even connected to its pelvis and couldn’t have supported its weight. But it clearly shows Basilosaurus’s evolution from land creatures. So that’s a giant step in the right direction. Even better, it establishes Ambulocetus as a clear link between the wolf-like creature and Basilosaurus.
Now these discoveries don’t completely solve the mystery. I mean, Ambulocetus is a mammal that shows a sort of bridge between walking on land and swimming. But it also is very different from the whales who know today. So really we are working with just a few pieces of a big puzzle.
Um…a related debate involved some recent DNA studies. Remember, DNA is the genetic code for any organism. And when the DNA from two different species is similar, it suggests that those two species are related. And when we compared some whale DNA with DNA from some other species, we got quite a surprise. The DNA suggests that whales are descendants of the hippopotamus. Yes, the hippopotamus!
Well, it came as a bit of a shock. I mean, that a four-legged land and river dweller could be the evolutionary source of a completely aquatic creature up to 25 times its size? Unfortunately, this revelation about the hippopotamus apparently contradicts the fossil record, which suggests that the hippopotamus is only a very distant relative of the whale, not an ancestor. And of course as I mentioned, that whales are descended not from hippos but from that distant wolf-like creature.
So we have contradictory evidence. And more research might just raise more questions and create more controversies. At any rate, we have a choice. We can believe the molecular data, the DNA, or we can believe the skeleton trail, but unfortunately, probably not both.
Um… and there have been some other interesting findings from DNA research. For a long time, we assumed that all whales that had teeth including sperm whales and killer whales were closely related to one another. And the same for the toothless whales, like the blue whale and other baleen whales, we assumed that they be closely related.
But recent DNA studies suggest that that’s not the case at all. The sperm whale is actually closely related to the baleen whale, and it’s only distantly related to the toothed-whales. So that was a real surprise to all of us.
官方真题Official10托福听力Lecture1题目文本
Question 1 of 6
What is the lecture mainly about?
A. Recent fossil evidence connecting whales and the hippopotamus.
B. Difficulties in the determining the evolutionary history of whales.
C. Similarities among ancient ancestors of whales.
D. Similarities between whales and other modern-day animals.
Question 2 of 6
According to the professor,what three aspects of the Ambulocetus fossil make Ambulocetus a likely bridge between land mammals and sea mammals?Click on 3 answers.
A. It had an elongated skeletal structure.
B. It strongly resembled a modern hippopotamus.
C. It had an unusually kind and thin tail for a whale.
D. It had limbs that could have been used for walking
E. Its skull had ear bones characteristic of land mammals
Question 3 of 6
According to the professor ,what does the discovery of Ambulocetus mean to researchers?
A. It fills a gap in the fossil evidence for whale evolution.
B. It has become less significant since the discovery of Basilosaurus.
C. It call into doubt the theory that whale evolved from land mammals.
D. It suggests that whales evolved more recently than was previously believed.
Question 4 of 6
What evidence suggests that whale are descendants of the hippopotamus?
A. Similarities between hippopotamus fossils and the Ambulocetus fossil.
B. Similarities in the genes of hippopotamuses and whales.
C. Similarities in the habitats of modern hippopotamuses and ancient whales.
D. Similarities in the skeletal structures of modern hippopotamuses and ancient whales.
Question 5 of 6
What is the professor's opinion about recent genetic studies relating to whale evolution?
A. They solve a long-standing mystery involving fossil evidence.
B. They contain significant errors.
C. They present evidence that conflicts with fossil evidence.
D. The findings of the various studies should not have surprised researchers.
Question 6 of 6
What does DNA evidence indicate about relationships among whales?
A. All modern whales descend from sperm whales.
B. Differences among toothed whales are less significant that was previously thought.
C. Not all toothed whales are closely related.
D. Sperm whale are more closely related to killer whales than was previously thought.
官方真题Official10托福听力Lecture1答案解析
Question 1 of 6
正确答案：B
题目解析：教授一开始就 说 We know whales are mammals and that they evolved from land creatures. So the mystery is figuring out how they became ocean dwellers.而接下来整片lecture就讲述了对于鲸鱼从陆生动 物变成海洋动物的过程的研究及遇到的问题，印证了鲸鱼的发展历史在目前很难得到准确结 论这个主旨。所以答案应该选B。
Question2 of 6
正确答案：ACD
题目解析：教授首先告诉大家Ambulocetus 的名字的意思就是walking whale that swims，提示了Ambulocetus 和鲸鱼之间可能有告诉的相关性，接下来则提到了一些正面 Ambulocetus可能是鲸鱼和陆生哺乳动物之间的过渡的特点：It clearly had four limbs that couldn’t have been used for walking，即答案D;It also had a long thin tail, typical of mammals, something we don’t see in today’s whales，即答案C;it also had a long skeletal structure，即答案A。
Question 3 of 6
正确答案：A
题目解析：听力材料中分析了Ambulocetus 的身体结构并解释了为什么这些结构特点证明 Ambulocetus 是鲸鱼和陆生哺乳动物之间的一个过渡，说明Ambulocetus 的发现填补了这个过渡期中的一些空白。B、C、D 在材料中都没有被提及。
Question 4 of 6
正确答案：B
题目解析：听力材料中提到通过 比较鲸鱼和 hippopotamuses 的DNA，得出鲸鱼是 hippopotamuses 的后代的结论，这个结论 是由鲸鱼的DNA 和 hippopotamuses 的相似性得到的。所以答案应选B。
Question 5 of 6
正确答案：C
题目解析：教授说通过化石(也就是身体结构)分析和通过 DNA 分析我们分别得到了 contradictory evidences，We can believe the molecular data- the DNA, or we can believe the skeleton trail, but unfortunately, not both。所以答案应该选C。
Question 6 of 6
正确答案：C
题目解析：教授提到 for the toothless whales, like the blue whale and other baleen whales, we assumed that they be closely related. But recent DNA studies suggest that that’s not the case at all.说明有牙齿的鲸鱼在DNA上并不一定相近。所以答案应该选C
以上就是小编为大家整理了官方真题Official10托福听力Lecture1文本+题目+答案解析，大家可以边借助官方真题Official模考软件听音频看看自己哪些地方听不懂，然后来看看原文，同时对练习托福听力精听也是很有帮助的。最后，小站教育编辑预祝大家托福考试能取得理想的成绩。
更多最新，最in的托福资讯，关注公众号：小站托福(ID：xiaozhantuofu2015)
