标题: OG13 CR74 [打印本页] 作者: lycorisss 时间: 2013-2-14 10:43 标题: OG13 CR74 求问各位CDers OG13 CR74这题呀~ Which of the following most logically completes the argument below? Using broad-spectrum weed killers on weeds that are competing with crops for sunlight, water, and nutrients presents a difficulty: how to keep the crop from being killed along with the weeds. For at least some food crops, specially treated seed that produces plants resistant to weed killers is under development. This resistance wears off as the plants mature. Therefore, the special seed treatment will be especially useful for plants that________. (A) produce their crop over an extended period of time, as summer squash does (B) produce large seeds that are easy to treat individually, as corn and beans do (C) provide, as they approach maturity, shade dense enough to keep weeds from growing (D) are typically grown in large tracts devoted to a single crop (E) are cultivated specifically for the seed they produce rather than for their leaves or roots 答案是C，不过想问下E OG上的解释是：A plant harvested for its root,fruits,or leaves ,rather than for its seeds ,would derive no less an advantage from resistance to weed killers in earlier stages of growth . 求翻译下这个解释呀~ 作者: yiqing2012 时间: 2013-2-14 23:38
额。。童鞋你发错地方了。。。