The reading passage talks about three damages caused by the "let it burn" policy, which are heavily criticized This claim completely contradicts the idea of the professor, which suggests this policy definitely have good influences.
First, the reading passage claims that the fire was detrimental to the trees and other vegetation. In contrast, the professor believes that the land which had been scorched was a better place for new plants which would increase the diversity because the fire provided opportunities for certain plants could not grow otherwise. For example, areas where trees were destroyed were taken over by smaller plants that needed open and an shaded place. What's more, seeds could survive there because they did not have to germinate in the high height places.
Second, the author states that the park wildlife was harmed too. On the contrary, the professor believes that animals could get benefits as well. The fired land replaced with small plants provided small animals, like rabbits and hares, an ideal habitat to live in. Also, predators which ate rabbits also increased, and as a result, the food chain would be stronger after the fire.
Third, according to the reading passage, the value of the tourist attraction would decrease which did harm to the national economy. However, the speaker argues that this phenomenon would not appear frequently. This time the low rainfall and strong wind cause the massive fire, which was not a frequent occurrence. But after this huge fire, this matter never occur. In the next year, the part still opens and it attracts many tourists every year.
The reading indicates three merits of using genetic modification to improve trees. However, the professor says there are potential problems and costs when using genetic modification method.
First, the reading says genetically modified trees are more likely to survive than unmodified trees. However, the professor refutes that genetic modified trees are unlikely to survive. Unlike unmodified trees, genetically modified trees are genetically uniform, so if they are exposed to environmental changes like climate changes that are not designed, they would all die.
Second, the reading indicates that genetically modified trees can bring lots of economic benefits. However, the professor argues that there are hidden costs of growing genetically modified trees. In fact , the seeds of genetic modified trees are more expensive and after planning those trees, farmers have to pay for the company.
Third, the reading implies that growing genetically modified trees can protect wild trees. Nonetheless, the professor thinks that actually local wild trees would be more damaged. Genetically modified trees are growing more aggressively than unmodified trees and modified frees would compete with wild trees for resource such as sunshine, soil nutrients and water. Consequenly, this situation is detrimental to wild tree’s growth.
The reading talks about three reasons of using ethanol fuel,which is supported by people to be used as the replacement of gasoline. However, the professor refutes that none of the reasons is convincing.
First, the reading says using ethanol fuel is detrimental to environment. However, the professor indicates that the use of ethanol fuel will not result in global warming. The process of growing corn, which absorb the carbon dioxide from the air, counteracts the release of carbon dioxide. So growing plants for ethanol production actually removes carbon dioxide from the atmosphere.
Second, the production of ethanol would reduce the plants needed by animals. However, the professor refutes that the production of ethanol does not reduce the resource of animals. Since people can produce ethanol using the part of plants which is not eaten by animals, the feeds of animals would not decrease.
Third, the reading implies that the price of ethanol would increase greatly. However, the professor argues that the price of ethanol fuel would compete with that of gasoline. Once people start to buy ethanol, ethanol producers would increase the production, leading to decrease of price. If ethanol production is 3 times greater than it is now, the cost would drop by 40 percent.
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发表于 2014-9-11 23:47:38
