Gortland has long been narrowly self-sufficient in bothgrain and meat. However, as per capita income in Gortland has risen toward theworld average, per capita consumption of meat has also risen toward the worldaverage, and it takes several pounds of grain to produce one pound ofmeat. Therefore, since per capita incomecontinues to rise, whereas domestic grain production will not increase,Gortland will soon have to import either grain or meat or both.
Which of the following is an assumption on which theargument depends?
(A) The total acreage devoted to grain production inGortland will soon decrease.
(B) Importing either grain or meat will not result in asignificantly higher percentage of Gortlanders' incomes being spent on foodthan is currently the case.
(C) The per capita consumption of meat in Gortland isincreasing at roughly the same rate across all income levels.
(D) The per capita income of meat producers in Gortlandis rising faster than the per capita income of grain producers.
(E) People in Gortland who increase their consumption ofmeat will not radically decrease their consumption of grain.
思路：需要解释的现象：after Greatwater Countypainted edge markings on all its narrow, winding roads, the annual accidentrate along those roads actually increased slightly.
2. 此现象中时间“after Greatwater County……”, 所以排除时间矛盾的选项;
B: 谓语动词canbe as difficult, 没有变化;
D: 谓语动词是involve, 较难判断是否是变化的。许多事故都是涉及到单个车翻下路，而不是两车碰撞。那很有可能原来的路上的情况也是这样的。所以不能解释为什么事故率上升;
E: no longer didso表明了一种变化，并且时间也符合(after….)。以前不在这条路上开车的driver, 现在开始在这条路上开车,所以事故率有了上升;