作业帮一道GMAT逻辑题Crops can be traded on the futures market before they are harvested if a poor corn harvest is predicted prices of corn futures rise; if a bountiful corn harvest is predicted prices of corn futures fall This morning meteorologists a
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/11 22:04:11
一道GMAT逻辑题Crops can be traded on the futures market before they are harvested if a poor corn harvest is predicted prices of corn futures rise; if a bountiful corn harvest is predicted prices of corn futures fall This morning meteorologists a
一道GMAT逻辑题
Crops can be traded on the futures market before they are harvested if a poor corn harvest is predicted prices of corn futures rise; if a bountiful corn harvest is predicted prices of corn futures fall This morning meteorologists are predicting muchneeded rain for the corn-growing region starting tomorrow.Therefore,since adequate moisture is essential for the current crop s survival prices of corn futures will fall sharply today.
Which of the following,if true,most weakens the argument above?
(C) The rain that meteorologists predicted for tomorrow is expected to extend well beyond the corn-growing region.
(D) Agriculture experts announced today that a disease that has devastated some of the corn crop will spread widely before the end of the growing season.
为什么不选C
一道GMAT逻辑题Crops can be traded on the futures market before they are harvested if a poor corn harvest is predicted prices of corn futures rise; if a bountiful corn harvest is predicted prices of corn futures fall This morning meteorologists a
根据原文我们知道作物的产量与期货价格呈负相关关系,丰收会降低价格,歉收会使价格上涨.这是大前提.
原文称已经预测到的充沛的降水会满足当前作物的生长需要,这意味着产量有保证.这是小前提.
原文的结论就是,农产品价格会降低.
C提到作物生长区之外的区域同样获得这次降水,这对作物产量是没有影响的.D提到农业专家今天宣称一种已经造成减产的病害在作物成熟之前会大面积蔓延.显然,D严重削弱了原文小前提的正确性,也就是说,产量其实并没有保证,而价格并不至于下降.所以,D这一新的前提的出现使原文的论证变得不具有说服力.