综合写作4

  Reading

  Endotherms are animals such as modern birds and mammals that keep their body temperatures constant. For instance, humans are endotherms and maintain an internal temperature of 37°C, no matter whether the environment is warm or cold. Because dinosaurs were reptiles, and modern reptiles are not endotherms, it was long assumed that dinosaurs were not endotherms. However, dinosaurs differ in many ways from modem reptiles, and there is now considerable evidence that dinosaurs were, in fact, endotherms.

  Polar dinosaurs

  One reason for believing that dinosaurs were endotherms is that dinosaur fossils have been discovered in polar regions. Only animals that can maintain a temperature well above that of the surrounding environment could be active in such cold climates.

  Leg position and movement

  There is a connection between endothermy and the position and movement of the legs. The physiology of endothermy allows sustained physical activity, such as running. But running is efficient only if an animal's legs are positioned underneath its body, not at the body's side, as they are for crocodiles and many lizards. The legs of all modern endotherms are underneath the body, and so were the legs of dinosaurs. This strongly suggests that dinosaurs were endotherms.

  Haversian canals

  There is also a connection between endothermy and bone structure. The bones of endotherms usually include structures called Haversian canals. These canals house nerves and blood vessels that allow the living animal to grow quickly, and rapid body growth is in fact a characteristic of endothermy. The presence of Haversian canals in bone is a strong indicator that the animal is an endotherm, and fossilized bones of dinosaurs are usually dense with Haversian canals.

  Listening

  Professor:

  Many scientists have problems with the arguments you read in the passage. They don't think those arguments prove that dinosaurs were endotherms.

  Take the polar dinosaur argument. When dinosaurs lived, even the polar regions, where dinosaur fossils have been found, were much warmer than today, warm enough during part of the year for animals that were not endotherms to live. And during the months when the polar regions were cold, the so-called polar dinosaurs could have migrated to warmer areas or hibernated like many modern reptiles do. So the presence of dinosaur fossils in polar regions doesn't prove the dinosaurs were endotherms.

  Well, what about the fact that dinosaurs have their legs placed under their bodies, not out to the side like crocodiles. That doesn't necessarily mean dinosaurs were high-energy endotherms built for running. There is another explanation for having legs under the body. This body structure supports more weight, so with the legs under their bodies, dinosaurs can grow to a very large size. Being large had advantages for dinosaurs, so we don't need the idea of endothermy and running to explain why dinosaurs evolved to have their legs under their bodies.

  Ok, so how about bone structure? Many dinosaur bones do have Haversian canals, that's true. The dinosaur bones also have growth rings. Growth rings are thickening of the bone that indicates periods of time when the dinosaurs weren't rapidly growing. These growth rings are evidence that dinosaurs stopped growing or grew more slowly during cooler periods. This pattern of periodic growth, you know, rapid growth followed by no growth or slow growth, and then rapid growth again, is characteristic of animals that are not endotherms. Animals that maintain a constant body temperature year-round as true endotherms do grow rapidly even when the environment becomes cool.

  一、阅读听力要点概括

  Reading Passage

  Main points: Evidence that dinosaurs were endotherms.

  Sub point 1: Polar dinosaurs found.

  Sub point 2: Leg position suggests endotherms.

  Sub point 3: Bone structure indicates endothermy.

  Lecture

  Attitude: Arguments. (Can’t prove endotherms.)

  Sub Point 1: Polar regions were warmer. (Migrate or hibernate.)

  Sub Point 2: Legs just for support more weight.

  Sub Point 3: Growth rings. (Periodic growth.)

  Answers

  二、范文逐段赏析

  Paragraph 1

  The professor actually contradicts the statements made in the reading passage. She is of the view that dinosaurs were not endotherms, or that they were not able to keep their body temperatures at a constant rate.

  此段功能:

  (Listening passage后文提到用L代替)

  (Reading passage后文用R代替)

  以L为主,作者开头段写出L反对R做出的观点。她认为恐龙不是暖血动物,或者不能把他们的体温维持恒定。

  此段结构:

  作者在开头段立刻表面了逻辑,随后总结了L的观点,准备开始辩论。

  Paragraph 2

  The professor disputes the issue of dinosaurs being endotherms. Based on the limited availability of fossils from the polar regions, she asserts that these regions were not as cold as they are today, and could sustain dinosaur life during warmer seasons. During harsh winters she believes that there is a possibility that the dinosaurs actually migrated to warmer regions.

  此段功能:

  以L的观点开头,作者说L不认为恐龙是暖血动物,因为当地的极地气候没有现在这么冷,在温暖的时候也许可以让恐龙存活。在冬季的时候恐龙可以迁移到更温暖的地方去。

  此段结构:

  此段为总分结构,在第一个极地问题的讨论上,L给了一系列证据支撑她的论点。

  Paragraph 3

  The issue of leg position and movement being used as a reason to classify the dinosaurs as endotherms does not satisfy the professor either. She says that dinosaurs had legs under their bodies to support their massive weights, and not to provide it with a body structure like other endothermic creatures, and onemore suited to running.

  此段功能:

  作者继续说L认为大腿位置也不能证明恐龙是暖血动物。L解释恐龙的大腿在躯干下面主要是用于支撑体重或者跑步,不是像其他的暖血动物一样。

  此段结构:

  总分结构。作者带出L观点之后详细解释了L的证据。

  Paragraph 4

  The professor acknowledges the presence of haversian canals but also points out that that the fossils show the presence of growth rings. These rings are due to the thickening of a developing bone.
 The thickening indicates that the dinosaurs weren’t actually growing continuously but were experiencing periods of both rapid growth and no growth in succession. She says this type of bone growth is characteristic of non-endothermic animals.

  此段功能:

  讨论第三个分论点,作者写明L承认harversian canals但是同时这些化石有生长年轮。生长年龄是因为恐龙生长期间的快慢差异导致的,这种现象是冷血动物特有的。

  此段结构:

  总分结构。第一句总结L观点。随后用新的例子打破R原来的理论。

  Paragraph 5

  Thus, it can be inferred that the professor challenges the passage by giving reasons supporting her position that the dinosaur is not an endotherm.

  此段功能:

  做最终总结,L给出了许多原因支持恐龙不是暖血动物

  此段结构:

  一句话作为收尾,呼应首段,L达到了证明效果。

  三、范文全篇总评

  1、 逻辑结构

  全文遵从总分结构,开头段做出总结,展望论点,表面逻辑。

  随后三段依照3个分论点依次展开。在分论点的论证中,作者阐明了L的态度, 补充新的证据,达到了一一驳倒R的效果。最后一段总结辩论效果达成。

  2、语言表达

  文章语言清晰,难度主要来自专业词,但是除了专业词汇并没有启用太多生词和长难句,其中可以借鉴的词句有:

  1. The professor disputes the issue of…

  教授反对了….的观点

  2. Acknowledge: 承认

  /recognize/confess/

  We acknowledge the need of revolution.

展开显示全文