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
疑惑在于A是不是说不同庄稼的种子之间的shade of color有很大的不同？ 如果是这个意思那不是能让那个新发明的机器更好地识别不同种子吗？ 这个a considerable degree of variation 应该怎么理解呢？
希望牛牛们帮助！作者: Western 时间: 2013-5-16 13:09
Weed is not seed. It's grass.作者: doudoucc 时间: 2013-5-16 18:53
同问a作者: Western 时间: 2013-5-17 06:15
The key is to separate weed from crop plants, not weed from another weed.作者: callmesoli 时间: 2013-5-18 15:34
