单选题 19. 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.
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.

【正确答案】 D

【答案解析】 D：选项取反。使用植物燃料→更经常开车→更多花费+环境破坏，削弱原文，正确。
A：该选项重复原文，不选。
B：本文讨论的是使用植物燃料时是否会产生更少的花费和污染，与汽车能不能同时使用这两种燃料无关，不选。
C：本文讨论的是使用燃料本身导致的环境破坏，和汽车的环境破坏是否全都归因于燃料无关，不选。
E：本文讨论的是改成植物燃料的司机自己的花费和环境破坏，与会有多少司机改用植物燃料无关，不进。