本帖最后由 zhangxiaohang1 于 2010-7-28 11:36 编辑
ARGUMENT207 - It is known that in recent years,industrial pollution has caused the Earth's ozone layer to thin, allowing anincrease in the amount of ultraviolet radiation that reaches the Earth'ssurface. At the same time, scientists have discovered, the population of aspecies of salamander that lays its eggs in mountain lakes has declined. Sinceultraviolet radiation is known to be damaging to delicate tissues and sincesalamander eggs have no protective shells, it must be the case that theincrease in ultraviolet radiation has damaged many salamander eggs andprevented them from hatching. This process will no doubt cause populationdeclines in other species, just as it has in the salamander species. WORDS: 440
TIME: 00:45:00
DATE: 2010/7/2612:34:46 The author conclude that all species' populationwill decline by the thinner ozone layer just because the declining ofsalamander in mountain lakes and its none-shell eggs. In his logical chain,there are several mistakes without which we could not agree with author'sconclusion. First, it's true that Earth's ozone layer is beingthinner, but whether it's the cause for the declining of the population ofsalamander is not clear. The causation between these two facts is open todoubt. In general, the competition between species is always the main causewhich leads to species' population declining. What's more, man's actions suchas pollution in water or air, killing them for food and so forth can also bethe causes. The fact that salamander's eggs without protect shells is notdirectly prove that their death are caused by ultraviolet radiation. In lakes,water could reflex and absorb part of ultraviolet radiation and as I know theratio of the absorption by water is not low. Therefore, to concludesalamander's declining attribute to the thinner ozone layer author should giveus more analysis and data directly proved this conclusion. For his second logical mistake, many salamandereggs death not equal to their population's declining, is easily to be refuted.Everybody knows some species always lay more eggs then they need to assure thatafter these eggs’ death by many reasons they still have enough eggs to keeptheir normal breeding and their species from the danger to be extinct. Forinstance, fishes and turtles are the representative species mentioned above. Ifauthor provides data about whether salamander’s way of breeding likes fishesand turtles’, it may contribute to accomplishing his logical chain. Finally, there is no reason to hastily generalizationthat other species' population declining, if exist, causing by thinner ozonelayer or to say its industrial pollution. Every species have its own way toreproduce and salamander may not be the sample whose reproducing way mostrepresentative and have the most similarity to other species’. As thedifferences between species’ way of reproduction such as other species’ eggswith shell and mammalian viviparous one the generalization are hasty, weak and unwarranted. In short,lacking evidence that salamander’s breeding way is the most typical one theauthor cannot convince me to his conclusion. In sum, the author's evidence accomplishes littletoward supporting his argument for species' population declining. To furtherbolster his conclusion the author must provide better evidence, perhaps thecausation between the declining and ultraviolet radiation and the reason why hecould generalization this phenomenon to other species. With those evidencesauthor's conclusion have more reliability to the readers. =======================================================================================
自改后
ARGUMENT207 -It is known that in recent years, industrial pollution has caused the Earth'sozone layer to thin, allowing an increase in the amount of ultravioletradiation that reaches the Earth's surface. At the same time, scientists havediscovered, the population of a species of salamander that lays its eggs inmountain lakes has declined. Since ultraviolet radiation is known to bedamaging to delicate tissues and since salamander eggs have no protectiveshells, it must be the case that the increase in ultraviolet radiation hasdamaged many salamander eggs and prevented them from hatching. This processwill no doubt cause population declines in other species, just as it has in thesalamander species.
WORDS: 450
TIME: 00:45:00
DATE: 2010/7/26 12:34:46
The authorconcludes that all species' populations are reduced by the thinner ozone layerjust because the declining of salamander in mountain lakes and its none-shelleggs. In his logical chain, there are several mistakes; unless solving them wecould not agree with author's conclusion.
First, it'strue that Earth's ozone layer is being thinner, but whether it's the cause forthe decreasing of the population of salamander is not clear. The causationbetween these two facts is open to doubt. In general, the competition betweenspecies is always one of the main causes which leads to species' populationdeclining. What's more, man's actions such as pollution in water or air,killing them for food and so forth can also be the causes. The fact thatsalamander's eggs are without protective shells is not a directly proof totheir death causing by ultraviolet radiation. In lakes, water could reflex andabsorb part of ultraviolet radiation and as I know the ratio of the absorptionby water is not low. Therefore, to conclude salamander's decreasing attributeto the thinner ozone layer author should give us more analysis and datadirectly proved this conclusion.
For his secondlogical mistake, many salamander eggs death is not equal to their population'sdeclining[5], is easily to be refuted. Everybody knows some species always laymore eggs then they need to assure that after these eggs’ death by many reasonsthey still have enough eggs to keep their normal breeding and their speciesfrom the danger to be extinct. For instance, fishes and turtles are therepresentative species mentioned above. If author provides data about whethersalamander’s way of breeding is similar to fishes and turtles’, it maycontribute to achieving his logical chain.
Finally, thereis no reason to hastily generalize that other species' population decreasing,if the decreasing exists, is caused by thinner ozone layer or to say itsindustrial pollution. Every species have its own way to reproduce andsalamander may not be the sample whose reproducing way most representative andhave the most similarity to other species’. As the differences between species’way of reproduction such as other species’ eggs with shell and mammalianviviparous one the generalization are hasty, weak and unwarranted. In short,lacking evidence that salamander’s breeding way is the most typical one theauthor cannot convince me to his conclusion.
In sum, theauthor's evidence accomplishes little toward supporting his argument forspecies' population declining. To further bolster his conclusion the authormust provide better evidence, perhaps the causation between the declining andultraviolet radiation and the reason why he could generalization thisphenomenon to other species. With those evidences author's conclusion have morereliability to the readers.
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