myice

GWD-6-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?

A. Every time a human being or other mammal exhales, there is some carbon dioxide released into the air.

B. The conversion of methane to electricity would occur at a considerable distance from the landfills.

C. 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.

D. Methane in the atmosphere is more effective in blocking the escape of heat from the Earth than is carbon dioxide.

E. The amount of methane emitted from the landfills could be reduced if the materials whose decomposition produces methane were not discarded, but recycled.

 

答案中必须体现二者的关系。E说如果将分解甲烷的原料循环使用，产生的甲烷会减少。这个明显不在原文的逻辑推理范围当中，和反对者的话没关系C说的是M将替代某种不会产生二氧化碳的燃料。燃料的替代与否跟本文章一点关系都没有，是无关选项。本文是在讨论如何减少温室效应不是讨论燃料。

D说甲烷比二氧化碳产生的温室效应更厉害，也就是说燃烧还是能减少温室效应的。D

myice

GWD-6-Q40:

It is theoretically possible that bacteria developed on Mars early in its history and that some were carried to Earth by a meteorite. However, strains of bacteria from different planets would probably have substantial differences in protein structure that would persist over time, and no two bacterial strains on Earth are different enough to have arisen on different planets. So, even if bacteria did arrive on Earth from Mars, they must have died out.

The argument is most vulnerable to which of the following criticisms?

It fails to establish whether bacteria actually developed on Mars.

It fails to establish how likely it is that Martian bacteria were transported to Earth.

It fails to consider whether there were means other than meteorites by which Martian bacteria could have been carried to Earth.

It fails to consider whether all bacteria now on Earth could have arisen from transported Martian bacteria.

It fails to consider whether there could have been strains of bacteria that originated on Earth and later died out.

Answer: D是正确的！如果地球上所有的细菌全部来自火星，当然不可能有两种不同的结构，IF这个成立，那么文章的结论说来自火星的灭绝了就错了！因为现有的细菌来自火星，但却没有灭！