求教prep Q4

gmatziyu

Which of the following most logically completes the argument?



A new machine for harvesting corn will allow rows to be planted only fifteen inches apart, instead of the usual thirty inches.Corn planted this closely will produce lower yields per plant.Nevertheless, the new machine will allow corn growers to double their profits per acre because __________.



(A) with the closer spacing of the rows, the growing corn plants will quickly form a dense canopy of leaves, which will, by shading the ground, minimize the need for costly weed control and irrigation

(B) with the closer spacing of the rows, corn plants will be forced to grow taller because of increased competition for sunlight from neighboring corn plants

(C) with the larger number of plants growing per acre, more fertilizer will be required

(D) with the spacing between rows cut by half, the number of plants grown per acre will almost double

(E) with the closer spacing of the rows, the acreage on which corn is planted will be utilized much more intensively than it was before, requiring more frequent fallow years in which corn fields are left unplanted
请问这题为什么不是D是A呢？
谢谢

逆时桢

文中已经说了密度过高的种植会让亩产下降，就不能简单的以倍数计算总产量的上升了，因此我本来选择的D错误。
A，    降低成本，正确。
B，    长得更高，和种植谷物的收益无关吧。
C，    需要更多化肥，成本上升，这是削弱同学。
E，    土地利用更充分，部分土地不被种植，这和利润上升无关的吧~


在和profit相关的题目当中，首先要考虑revenue，其次考虑cost~