综合写作15
Reading
The cane toad is a large (1.8 kg) amphibian species native to Central and South America. It was deliberately introduced to Australia in 1935 with the expectation that it would protect farmers' crops by eating harmful insects. Unfortunately, the toad multiplied rapidly, and a large cane toad population now threatens small native animals that are not pests. Several measures have been proposed to stop the spread of the cane toad in Australia.
One way to prevent the spread of the toad would be to build a national fence. A fence that blocks the advance of the toads will prevent them from moving into those parts of Australia that they have not yet colonized. This approach has been used before: a national fence was erected in the early part of the twentieth century to prevent the spread of rabbits, another animal species that was introduced in Australia from abroad and had a harmful impact on its native ecosystems.
Second, the toads could be captured and destroyed by volunteers. Cane toads can easily be caught in simple traps and can even be captured by hand. Young toads and cane toad eggs are even easier to gather and destroy, since they are restricted to the water. If the Australian government were to organize a campaign among Australian citizens to join forces to destroy the toads, the collective effort might stop the toad from spreading.
Third, researchers are developing a disease-causing virus to control the cane toad populations. This virus will be specially designed: although it will be able to infect a number of reptile and amphibian species, it will not harm most of the infected species; it will specifically harm only the cane toads. The virus will control the population of cane toads by preventing them from maturing and reproducing.
Listening
The cane toad won’t be as easy to get rid of as the reading suggests. The measures proposed by the reading are likely either to be unsuccessful or to cause unwanted environmental damage.
First of all, a national fence probably won’t stop the spread of the toad. That’s because young toads and toad eggs are found in rivers and streams. No matter where the fence is located, at some point there will be rivers or streams flowing from one side to the other. These waterways will be able to carry the young toads and their eggs to the other side. Since it’s only necessary for a few young toads or eggs to get through the fence in order to establish population on the other side, the fence is unlikely to be effective.
Secondly, a massive group of volunteers could have success trapping and destroying toads. But it’s likely that these untrained volunteers would inadvertently destroy many of Australia’s native frogs. Some of which are endangered. It’s not always easy to tell the cane toad apart from native frogs especially when it’s young.
Third, using the virus is a bad idea because it could have terrible consequences for cane toads in their original habitat in Central and South America. You might be wondering how can a virus released in Australia cause harm in the America. Well, Australian reptiles and amphibians are often transported to other continents by researchers or pet collectors for example. Once the animals infected by the virus reach Central and South America, the virus will attack the native cane toads and devastate their populations. That would be and ecological disaster because in the America cane toads are a native species and a vital part of the ecosystem. So if they are eliminated, the whole ecosystem will suffer.
一、阅读听力要点概括
Reading Passage
Main points: Several measures are proposed to stop Cane Toad spreading.
Sub point 1: Build a national fence.
Sub point 2: Volunteers can destroy toads.
Sub point 3: Virus can control the cane toad populations.
Lecture
Attitude: Unsuccessful or unwanted damage.
Sub Point 1: Fence won’t stop the spread. (Eggs in rivers and streams, a few can pass the fence.)
Sub Point 2: Volunteer can destroy native frogs. (Untrained, frogs endangered.)
Sub Point 3:Virus can be transferred to America. (By reptiles and amphibians, Disaster for ecosystem.)
Answers
二、范文逐段赏析
Paragraph 1
The lecturer argues against the three measures mentioned in the reading passage thought to reduce the population of the cane toad, a species introduced to the Australian continent.
此段功能：
(Listening passage后文提到用L代替)
(Reading passage后文用R代替)
以L的观点为主要观点，作者说L反对R中提到的三点，并总结了要解决的问题：如何解决澳洲大陆上的蟾蜍数量。
此段结构：
作者用一句话总结了全文讨论的问题，并告诉大家全文逻辑为相反。极其简练直接，随即展开全文辩论。
Paragraph 2
The lecturer argues that the first measure, a national fence, would not prevent the flow of streams or rivers and, therefore, would allow young toads or toad eggs to travel through the fence. The reading passage, however, argues that such a fence would effectively cut off the route that animals use to establish colonies and expand in population.
此段功能：
以L的观点起头，谈第一种方法，全国栅栏并不能阻止小溪河流，这样小蟾蜍或者蟾蜍卵可以通过栅栏继续传播。所以R中提到的栅栏方法没有用。
此段结构：
此段为分分结构，从L的辩论开始，列举了栅栏会失效的证据，最后达到说明R中的栅栏是无用的目的。
Paragraph 3
Regarding the second measure, recruiting a large group of volunteers, the lecturer explains that volunteers often have difficulty distinguishing between cane toads and native frogs, which are an endangered species. Therefore, volunteers might unintentionally kill members of both species. The reading passage gives the opposite view: organizing a large group of volunteers to join an extermination campaign could speed the destruction of cane toads.
此段功能：
继续转入下一方法，志愿者杀蟾蜍方案。L解释到这些志愿者很难分辨蟾蜍和当地的珍贵青蛙，这样会造成无辜的伤害。所以R中提到的这个方法，也是行不通的。
此段结构：
此段为分分结构，先列出L中举的证据，最后达到说明R的想法不周全的结果。
Paragraph 4
Finally the lecturer objects to the third measure: using an infectious virus to kill the population of toads. She points out that a virus intended to eliminate Australia’s cane toad population could be transmitted to other continents where cane toads are an essential part of other local ecosystems. This is in direct contrast to the claim in the reading passage, which indicates that an infectious virus could be developed to stop the reproduction of cane toads without harming other species.
此段功能：
最后一个办法是用病毒杀死蟾蜍。在讨论中，L指出在澳洲能杀死蟾蜍的病毒可能会被带到别的大陆，在那里蟾蜍是当地生态圈中的不可缺少的一环，这样的后果目的直接和R中提到的完全相反，R认为病毒能只杀死澳洲蟾蜍而不伤害别的物种。
此段结构：
分分结构，详细列举L的证据和后果，再告诉读者与其相反的恰好是R的结论。达到反驳R的目的。
三、范文全篇总评
1、 逻辑结构
全文遵从总分结构，开头段直接一句话总结+逻辑，展开全文反驳基调。
随后三段依照3个分论点依次展开。在分论点的论证中，作者诠释了L的论点和论据，随后再摆出R的证据和论点时，读者已经能清晰感觉到R的错误。十分有力的反对了R。
2、语言表达
本文用词并不复杂，但是论据的陈列十分有章法。其中可以借鉴的有：
1. Regarding the…(论点)，the lecturer explains that….(可以驳倒或者支持论点的证据。)
2. Objects：反对，物体，对象
/Oppose/ Target/
He objects the proposal after a detailed analysis.