GMAT考试写作指导：Argument范文十九

　　79. This newspaper editorial concludes that our city should build a plant for burning

　　trash in order to avoid the serious health threats associated with many landfills. The

　　author adds that an incinerator could offer economic benefits as well, since incinerators

　　can be adapted to generate small amounts of electricity for other uses, and since ash

　　residue from some kinds of trash can be used as a soil conditioner. Even if these claims

　　are true, the authors argument is unconvincing in three important respects.

　　To begin with, the author fails to consider health threats posed by incinerating

　　trash. It is possible, for example, that respiratory problems resulting from the air

　　pollution caused by burning trash might be so extensive that they would outweigh the

　　health risks associated with landfills. If so, the authors conclusion that switching to

　　incineration would be more salutary for public health would be seriously undermined.

　　Secondly, the author assumes that discontinuing landfill operations would abate

　　the heath threats they now pose. However, this is not necessarily the case. It is possible

　　that irreversible environmental damage to subterranean water supplies, for example, has

　　already occurred. In this event, changing from landfills to incinerators might not avoid

　　or abate serious public health problems.

　　Thirdly, the authors implicit claim that incinerators are economically

　　advantageous to landfills is poorly supported. Only two small economic benefits of

　　incineration are mentioned, while the costs associated with either burning trash or

　　switching refuse disposal systems are ignored. In all likelihood, such costs would be

　　significant, and may very well outweigh the economic benefits.

　　In conclusion, the authors argument provides inadequate justification for

　　switching from one disposal system to the other. As it stands, the argument takes into

　　account only a limited number of benefits from the change, while addressing none of its

　　costs. To better evaluate the argument, we must first examine all the health risks posed

　　by each refuse disposal system and conduct a thorough cost-benefit analysis of each

　　system, taking account of the cost of the new system, the cost of the changeover itself,

　　and the expected costs to the community of health problems resulting from each system.