A plant-based automobile fuel has just become available in Ternland. A car can be driven as far on a gallon of the new plant-based fuel as a car can be driven on a gallon of gasoline, but a gallon of the plant-based fuel both costs less and results in less pollution. Therefore, drivers in Ternland who switch to it will reduce the amount they spend on fuel in a year while causing less environmental damage.
1. Which of the following is an assumption on which the argument relies?
A. There is no expense associated with operating an automobile that is higher when the automobile uses the plant-based fuel than when it uses gasoline.
B. Automobiles that have been operated using the plant-based fuel can no longer be operated using regular gasoline.
C. The environmental damage attributable to automobiles is due almost entirely to the production and combustion of fuel automobiles use.
D. The advantages of the plant-based fuel over gasoline will not lead those who switch to the plant-based fuel to do more driving.
E. Most drivers in Ternland will switch from gasoline to the plant-based fuel
白话版讲解:
以上论证要成立,必须依靠下列哪一个前设?
A. “和烧汽油燃料比起来,汽车烧新型燃料,和使汽车运行相关的费用不会更高。”
意思就是,司机想,可不要我换了新型燃料,燃料钱是省了,其他方面的费用升起来了,最后花的钱比少汽油燃料更多了。
乍一看这个选项好像是对的。但因为文章最后的结论是“will reduce the amount they spend on fuel in a year”,所以即使除燃料外的其他费用增多了(也就是说A前设不成立),只要司机花在fuel的上的钱减少了,文章最后的结论就成立。所以文章结论不是必须依靠A前设。所以A选项错误。
B. “用过新型燃料的汽车,就用不了汽油了。”
即使这个前设不成立——用过新型燃料的汽车,还可以用汽油,“这些司机一年下来花在燃料上的钱,可以降低”这一结论,仍然可以成立。所以B选项错误。
C. “汽车造成的污染几乎全部来自汽车燃料(的生产和燃烧)”。
即使汽车造成的污染不是几乎全部由汽车燃料导致 ,比如汽车造成的污染有很大一部分是来自汽车油漆,一辆汽车从烧汽油改成用新型燃料,还是可以导致其造成的总污染减少的。即燃料造成的污染占汽车总污染的比例,和换燃料会不会降低总污染这件事,是没有关系的。所以C选项错误。
D. “从烧汽油换成烧新型燃料的那些司机不会因为新型燃料优点太多而多开车”。
有的司机原来每天开两次车跑十来公里,换了新型燃料以后,发现新型燃料好便宜啊,就每天开七八次车跑五六十公里了。假如那些司机确实这样做,尽管新型燃料的单价便宜污染少,但是汽车行驶里程增加后,还是会导致一年下来花的钱和造成的污染,比烧汽油的情况多。所以D选项正确。
E. “Ternland的大部分司机都从烧汽油换成烧新型燃料”。
即使Ternland只有三个司机从烧汽油换成烧新型燃料,这三个司机一年下来花在燃料上的钱,会降低;他们的汽车产生的污染,也会减少。所以文章结论成立不需要“大部分司机换用新型燃料”这个前设。所以E选项错误。