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.
这个题目。。。正确答案是D ，可是我真的没有搞明白D 的逻辑？？甚至连意思好像都不太明白？解释一下吧~谢谢了GWD1-Q40: Until mow, only injectable vaccines against influenza have been available.  arents are reluctant to subject children to the pain of injections, but adults, who are at risk of serious complications from influenza, are commonly vaccinated. A new influenza vaccine, administered painlessly in a nasal spray, is effective for children. However, since children seldom develop serious complications from influenza, no significant public health benefit would result from widespread vaccination of children using the nasal spray. Which of the following is an assumption on which the argument depends? A. Any person who has received the injectable vaccine can safely receive the nasal-spray vaccine as well. B. The new vaccine uses the same mechanism to ward off influenza as jnjectable vaccines do. C. The injectable vaccine is affordable for all adults. D. Adults do not contract influenza primarily from children who have influenza. E. The nasal spray vaccine is mot effective when administered to adults. 正确答案是D，我把选项带进去，难道文章的逻辑是:因为大人不给小孩注射，而成人没有被小孩感染（D），所以，医疗机构得不到好处？是这样的吗？？
-- by 会员 水色青空 (2010/2/6 21:48:27)
Q1：
事实：有一种新的除杂草的机器，通过区分杂草和庄稼的光亮程度（色泽）来把杂草揪出来。
结论：以后不用手动除杂草了。
问题：什么能让这个结论更有力？
D就是说以后的庄稼可以通过基因技术，在不改变庄稼其他属性的前提下，使得他们的光亮色泽与众不同的体现出来。
这样的确可以帮助除杂草的机器啊，因为光泽越是突出，它辨认杂草和庄稼的能力就越强啊。
Q2：
事实：大人感冒后，并发症很厉害，所以大人愿意打疫苗。
事实：小孩不喜欢打疫苗，因为怕痛。
事实：小孩感冒后，并发症不厉害。
事实：发明了一种专门为小孩设计的不痛的疫苗。
结论：其实这种新疫苗没用，反正小孩也没有并发症，无所谓。
问题：这个结论的前提条件是是什么？
小孩并发症不厉害，只说明小孩自己不是很怕感冒的危害。但小孩感冒后，倒霉的不仅仅是得了感冒的小孩，因为感冒会传播啊。除非小孩不会传给大人感冒，小孩还是应该接受疫苗的，因为可以防止大人得病。
所以结论成立的前提条件就是感冒的小孩不是大人得到感冒病菌的来源。 | 
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发表于 2010-2-6 21:48:27
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