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托福TPO21綜合寫作(閱讀+聽力文本)

2017/4/17 13:06:24來源:新航道作者:新航道

摘要: 上海新航道托福小編給考生們帶來了托福TPO21綜合寫作,希望可以幫助廣大托福考生輕松備考托福。

   上海新航道托福小編給考生們帶來了托福TPO21綜合寫作,希望可以幫助廣大托福考生輕松備考托福。


  TPO 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 hardier 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.

  以上就是小編為大家?guī)黻P(guān)于托福TPO閱讀資料供大家閱讀參考,新航道托福資料頻道將第一時(shí)間為考生發(fā)布最全、最新、最專業(yè)的托福資訊及托福考試資料及機(jī)經(jīng).





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