GWD1-33求解释！

cherryfish1209

GWD1-Q33:

A company plans to develop a prototype weeding machine that uses cutting blades with optical sensors and microprocessors that distinguish weeds from crop plants by differences in shade of color.  The inventor of the machine claims that it will reduce labor costs by virtually eliminating the need for manual weeding.

Which of the following is a consideration in favor of the company’s implementing its plan to develop the prototype?

A There is a considerable degree of variation in shade of color between weeds of different species.

B The shade of color of some plants tends to change appreciably over the course of their growing season.

C When crops are weeded manually, overall size and leaf shape are taken into account in distinguishing crop plants from weeds.

D Selection and genetic manipulation allow plants of virtually any species to be economically bred to have a distinctive shade of color without altering their other characteristics.

E Farm laborers who are responsible for the manual weeding of crops carry out other agricultural duties at times in the growing season when extensive weeding is not necessary.

答案是E，但是没有明白E说的是什么意思啊。。。。知道题目的逻辑链是要证明这个prototype可以分别weed跟crop

yangrryq

这个题有点搞，正解的确是e,这里的consideration,可以理解为一种前提，assumption.意思是说那些农民在作物生长季节不会因为新机器的发明而无事可做。如果没有这个前提条件，农民在作物生长季节没事情做，那这个机器的发明就不能reduce labor costs。因为这些农民一直都在，现在因为机器的发明，他们解放了，但是他们的工资还在，labor costs没有变化。