托福考满分写作练习

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Official 21 Task 1
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 natural trees; that is, they are more likely to survive than their unmodified counterparts. In Hawaii, for example, a new pest-resistant species of papaya tree has been developed in response to ringspot virus infestations that have repeatedly damaged the native papaya-tree population. Planting the genetically modified papayas has largely put an end to the ringspot 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 wood, fruit, or other products—and be hardier. This allows tree farmers 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 or 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.

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