以下是引用dingrhan在2005-6-13 16:49:00的发言:答案有两个版本呀 B或D。 所以才要讨论呀,亲爱的MM!
嘿嘿,我的意思是我倾向于选d。。。
但是!!刚才又看了一遍题目,有倒戈的倾向...
题目说改良品种有bulabula的优点,比如减少农药用量,减少成本等等,所以会被推广...大多数优点都是基于抗虫性提高,农药用量减少,所以成本才会被减少,农民收入才会提高...
那么非改良品种如果本来就没用多少农药,那改良后的一切好处都会变得不明显...所以B有那么一点可以判断推论正误的意思在里面
可是有个NECESSARY不好...如果B说的是Whether farmers typically use agricultural pesticides in large amount for the conventional crops to prevent crop damage...我就选B...
就目前看来...我还是选D...如果改良后产量锐减,那么改良优点被抵消,则不会被推广。
B) Whether farmers typically use agricultural pesticides in larger amounts than is necessary to prevent crop damage
D) Whether seeds genetically engineered to produce insect-resistant crops generate significantly lower per acre crop yields than do currently used seeds.
[此贴子已经被作者于2005-6-13 17:37:19编辑过] |