以下是引用kokusanhin在2008/5/31 23:41:00的发言: Hey guys, the answer should be E.
For those of you who are consultants and have done some operation benchmark projects, rule number 1 is to establish the BASELINE.
We cannot say whether the genetically modified (GM) cottons are more insect resistant simply by comparing the amount of pesticides used by different farmers (some picked the GM cotton, some don't), unless we know the amount they had originally used.
For example, if 1) farmer A had used 100 KG of DDT for his 100-acre cottons when he planted normal seeds and farmer B had used only 50 KG (can be find out once the question in E is answered) and 2) after using GM cotton, farmer A would only need 49 KG (slightly less than 50), the GM cotton certainly performed well to resist insects, with a saving over 50%... Therefore, it would economically benefit all farmers to plant GM cotton.
不同意以上的解释, E 的意思是种新品种棉花前是否超大量使用农药。其实这明显是无关选项,题干已经说明,新旧品种农药使用量的差别是 slight 的。举一个极端例子: 种植100 公顷的新品种棉花只比旧品种棉花少用 1 kg。新种子比旧种子贵 $200. B,如果旧品种所用农药价格比其他作物的高,eg:$10000/kg,省 1kg 就省 $10000,农民还是赚的。 E,假设农药价格没有特别高,$1/kg, 就算之前你用 1000000kg,现在只省了 1 kg,农民还是亏。(我省的就只有 1kg,我以前用多用少有关系吗?) 因此本题绝对选 B。 当然,我承认 B 的表达不够直接,如果改成,旧品种棉花所用农药价格比新的要贵,大家就没什么好争了。但B项的表达就是 ETS 设的套,特意拉上 other crop 这个貌似无关的因素,其实 B 的关键是 expensive。 |