以下是引用zyzcdcdcd在2006-9-26 15:36:00的发言:Q32: Proposal: Carbon dioxide and methane in the atmosphere block the escape of heat into space. So emission of these “greenhouse” gases contributes to global warming. In order to reduce global warming, emission of greenhouse gases needs to be reduced. Therefore, the methane now emitted from open landfills should instead be burned to produce electricity.
Objection: The burning of methane generates carbon dioxide that is released into the atmosphere.
Which of the following, if true, most adequately counters the objection made to the proposal?
- Every time a human being or other mammal exhales, there is some carbon dioxide released into the air.
- The conversion of methane to electricity would occur at a considerable distance from the landfills.
- The methane that is used to generate electricity would generally be used as a substitute for a fuel that does not produce any greenhouse gases when burned.
- Methane in the atmosphere is more effective in blocking the escape of heat from the Earth than is carbon dioxide.
- The amount of methane emitted from the landfills could be reduced if the materials whose decomposition produces methane were not discarded, but recycled.
我认为counters the objection made to the proposal表示的就是(双重否定)支持这个proposal因为我感觉proposal里并没有objection.. 答案恰恰相反,请NN们指教 我是这么理解的,c和m是使全球变暖的主要原因,为了不让全球变暖,那些grasshouse gas就要减少排放,所以那些垃圾堆放出来的m应该把它燃烧掉,来发电 objection就怀疑说:燃烧掉m也会产生c而排放到大气中(就是燃烧c没用,也会是全球变暖) 题目问:那一个可以反驳objection(只要说燃烧m不会产生c或不会是全球变暖就可以了) c说,那些用来燃烧发电的m其实是一种燃料的替代品,而这种替代品燃烧不会任何的grasshouse gas(既然m是这种燃料的替代品,就说明用来发电的m在燃烧时也不会产生grasshouse gas,这样就反驳了objection) 嘿嘿,不知道理解的对不对,还请高手指点 |