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TPO21 综合写作 参考范文

(2012-05-17 21:43:34)
标签:

托福

综合

写作

教育

分类: 托福教学

The lecturer points out three different shortcomings of genetically modified trees. In the aspects of adaptation, economic lucrativeness, and environmental value, they never have overwhelming advantage over natural trees. That means the points made in the reading are partial and biased.

 

First, genetic modification doesn’t necessarily make a natural tree more resistant to environmental adversities. Although genetic reconstructing may make a species stronger in a specific condition as the reading indicates, the new strain lakes the genetic diversity of a natural species. Thanks to the marginal differences between individuals, there can always be some survivors among natural species following a large interruption like climate change or pest invasion. But similar changes may cause the extinction of a genetically modified species for their unification in characteristics.

 

Second, tree farmers don’t get guaranteed economic benefits if they plant genetically new strains. Companies that develop the new plants always charge farmers higher prices for artificially improved seeds, and receive money from farmers each time they grow the same plant. Such company policies and law will deprive farmers of the gaining mentioned in the reading.

 

Third, genetically modified trees don’t promise to protect wild trees. Actually, since they can grow faster with fewer resources, they are more ecologically invasive. Normally they outcompete natural trees by grasping natural resources like sunshine, water and soil. It’s far from the idealistic situation described in the reading.

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