综合写作21
Reading
Genetic modification, a process used to change an organism’s genes and hence its characteristics, is now being used to improve trees through genetic modification. It is possible to create trees that produce more fruit, grow faster, or withstand adverse conditions. Planting genetically modified trees on a large scale promises to bring a number of benefits.
First, genetically modified trees are designed to be harder than nature trees; that is, they are more likely to survive than their unmodified counterparts. In Hawaii, for example, a new pest-resistant species of papaya trees has been developed in response to ring spot virus infections that have repeatedly damaged the native papaya tree population. Planting the genetically modified papayas has largely put an end to the ring spot problem.
Moreover, genetically modified trees promise to bring a number of economic benefits to those who grow them. Genetically modified trees tend to grow faster, give greater yields of food, fruit, or other products and be hardier. This allows tree farmer to get faster and greater returns on their farming investment and save on pesticides as well.
Finally, the use of genetically modified trees can prevent overexploitation of wild trees. Because of the growing demand for firewood and building timber, many forests around the world are being cut down faster than they can be replaced. Introducing genetically modified trees, designed for fast growth and high yield in given geographic conditions, would satisfy the demand for wood in many of those areas and save the endangered native trees, which often include unique or rare species.
Listening
Sure, there are some benefits to plant genetically modified trees, but, are these trees as really great as they first sound? When you examine the subject firstly, there are some serious problems and costs associated with genetically modified trees.
First, genetically modified trees may be resistant to one particular condition. But that doesn’t necessarily ensure their survival. You see, a typical non modified trees’ population is genetically diverse. That means that for most threatening conditions, or climate, whatever, there will be at least some individual tress of any given species of tree that are resistant. So even if most of one kind of trees are killed, those few resistant tress will survive and ensure the survival of that species of tree. But genetically modified trees are genetically much more uniform. So if they’re exposed to an environmental challenge they have not been designed for, they all die. So if the climate changes, the genetically modified trees will likely to be completely wiped out.
Now as to the second point, they’re hidden costs associated with genetically modified trees. You see, the company that genetically modify the tree can charge tree farmers more for its seeds than un- genetically modified trees would cost. Also, as you’ve grown the tree, you can’t just collect the seeds and plant the new tree for free. By law, you have to pay the company every time you plant.
And finally, genetically modified trees might actually cause even more damage to the local wild trees. You see, genetically modified trees often grow more aggressively than natural trees do. And, genetically modified trees are typically planted among natural trees. As a result, the genetically modified trees outcompete the native trees for resources, sunlight, soil, nutrients, and water, eventually crowding out the natural trees.
一、阅读听力要点概括
Reading Passage
Main points: Genetic modification on large scale will bring benefits.
Sub point 1: Can be completely wiped out by certain environment.
Sub point 2: Modified trees are economically better.
Sub point 3: Modified trees grow fast and save wild trees.
Lecture
Attitude: Against. (Serious problem and associated cost.)
Sub Point 1: There are effective ways to stop mussels in today’s knowledge
Sub Point 2: Hidden costs associated like seeds.
Sub Point 3: Do more damage to wild trees. Grow so fast and outcompete the wild tree.
Answer
二、范文逐段赏析
Paragraph 1
The lecturer points out three different shortcomings of genetically modified trees. In the aspects of adaptation, economic lucrativeness, and environmental value, they never present overwhelming advantages compared with natural trees. This means the points made in the reading are partial and biased.
此段功能：
(Listening passage后文提到用L代替)
(Reading passage后文用R代替)
文章首先总结了三个分论点，十分新颖。三个分论点从三方面出发，环境适应性，经济有利性，环保价值性。然后写到L告诉大家R在三个方面的观点都是片面的，改造树和野生树在这三方面的比较并没显出绝对优势。确认了相反的逻辑关系，准备开始辩论。
此段结构：
此段为分总结构，列举三个要讨论的方面，然后才说L对R的意见，为接下来的辩论做好了充足的准备。
Paragraph 2
First, genetic modification doesn’t necessarily make a natural tree more resistant to environmental adversities. Although genetic modification may allow a species to manifest certain strengths in specific conditions, as the reading indicates, the new type lacks the genetic diversity of a natural species. Thanks to the marginal differences between individual trees, there can always be some survivors among natural species following a large interruption like climate change or pest invasion. But such changes may cause the distinction of a genetically modified species for their unification in characteristics, decreasing their overall survivability in many cases.
此段功能：
讨论第一个环境适应性方面的论点。L指出改造树并不一定在任何情况下都比野生树更强壮。因为改造树的基因非常单一，而不像野生树一样随机分布。在新恶劣天气情况下，改造树可能因为没有对抗基因而全部死亡，野生树里却千差万别，相对应的个体树会存活而不会导致与灭族。所以改造树的整体存活率是不高的。
此段结构：
此段为总分结构，陈列证据十分对称，Although but句型很好的列举了相对立的观点和证据。最后证明R之前的论点不可取。
Paragraph 3
Second, tree farmers don’t get guaranteed economic benefits if they plant genetically new strains. Companies that develop new plants always charge farmers higher prices for artificially improved seeds, and receive money from farmers each time farmers grow that same plant. Such laws and company policies can deprive farmers of any economic gain mentioned in the reading passage.
此段功能：
第二个经济有利性的讨论中。L的观点是农民使用改造树不一定能有好收益。收益包括成本和产出，改造树成本很高，而且公司会对农民重复收费。这种政策使得R提到的产出高也没有用。
此段结构：
此段为总分结构，L表明了自己观点后，用了一大段证据支撑改造树的成本高。从而到达了驳倒R的最后收益一定高的道理。
Paragraph 4
Third, genetically modified trees don’t promise to protect wild trees. In fact, since they can grow faster with fewer resources, they are more ecologically invasive than normal trees. Normally, they are able to outpace and stifle the growth of natural trees by using the available natural resources like sunshine, water and soil. It’s far from the idealistic situation described in the reading.
此段功能：
最后，L说改造树不一定能保护野生树。因为改造树由于生长快，所以侵略性强，和野生树同时种植很容易在抢夺资源中抑制野生树，反而没达到R本来保护野生树的目的。
此段结构：
此段还是总分结构。先表明L的观点，为了证明观点，从生长过程中充分了解了改造树对野生树的可能的危害，从而针锋相对的反驳了R的观点。
三、范文全篇总评
1、 逻辑结构
全文逻辑架构相当严密，第一段就简介指明了要论证的三方面。随后三个论段，对R所说的3个优势进行了一一批判。在过程中，作者也是严密按照R证明一个观点的顺序，在文中列举L相对应的条件。反驳十分有力。
2、语言表达
文中启用了一些生词，句式也十分紧凑，其中值得借鉴的有：
1. In the aspects of adaptation, economic lucrativeness, and environmental value, they never present overwhelming advantages compared with natural trees.
In the aspects of (对于A,B,C这几个面来说), they never (他们从未，证明，呈现某论点)
Adaptation: 适应
/Adjustment/Modification/
Lucrativeness： 有利可图的
/Profitablility/Gainfulness/
2. Distinction： 区别，特征，个性
There is a distinction between what he says and what he does.
3. Deprive: 剥夺，免去
/loot/rob/
We have no right to deprive their life.