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?

There is a considerable degree of variation in shade of color between weeds of different species. The shade of color of some plants tends to change appreciably over the course of their growing season. When crops are weeded manually, overall size and leaf shape are taken into account in distinguishing crop plants from weeds. 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. 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.

Here, why E is wrong? I think probably farm labors who carry out other duties because of new machine will indeed reduce the labor costs.

Dizzy now, could any NN help me?

原文是说公司想发展一种割草机，这种割草机是通过感光器和微处理器区别杂草和庄家的。同时发明者说这将大大减少劳动成本，因为它根本不再需要人工除草了。

问题问下面哪一条支持了公司发展这种机器。

D选项实际上是说了一个条件使得这种割草器具有实用价值。