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.

Would anybody tell me why the answer is D

Thanks a lot!!

谁能用中文在解释一下。。。

大概是这样：现在使用“selection and genetic manipulation "来经济地种植作物，这种方法能使培养出来的几乎所有作物的shade of color 独一无二，而不会改变其他性质。这样一来，这个割草机就轻松了，只要分辨"shade of color" ，该计划也就可行。

（另：真不明白为什么这个选项要牵扯到“selection and genetic manipulation", 难道这是现代种植必用的方法？）

不好意思，小声问一句，为什么E不对？plan的目的是reduce the labor cost，E说除杂草省下的时间可以做别的，那就是省了labor cost...而D里面说的高科技的冬冬实际上是不能直接strengthen的啊，因为如果农民都不用高科技的冬冬那不就没戏了？

臆测一下...

Thanks, very clear explanation.

我也误选E，把工人时间省下来作别的事情也是reduce labor cost的支持阿