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 underdevelopment. This resistance wears off as the plants mature. Therefore, the special seed treatment will be especially useful for plants that ______.


produce their crop over an extended period of time, as summer squash does

produce large seeds that are easy to treat individually, as corn and beans do

provide, as they approach maturity, shade dense enough to keep weeds from growing

are typically grown in large tracts devoted to a single crop

are cultivated specifically for the seed they produce rather than for their leaves or roots

考题讲解

情景:用广谱除草剂除去与农作物竞争的杂草有一个问题:如何保证农作物不和杂草一起被消灭。对至少有一些农作物来说,经特殊处理的可以对抗除草剂的种子正在生产中,但这种对抗性在植物成熟之后就消失了。因此,这种特殊的种子适用于某些植物。问的是这些植物是什么。

推理:由于推理文段中没有结论,所以其为演绎推理。对抗性在植物成熟之后消失,说明这种种子只能在幼年期保护植物,而在植物成熟之后需要植物自己保护自己。 


选项分析:

A选项:像夏季南瓜一样,生产庄稼的时间很长。能生产庄稼的时候,必然是植物成熟的时候,这会使得该植物更不被这种种子所适用了。

B选项:生产容易被操作的大种子,像玉米和大豆一样。种子大小和能否在植物成熟之后需要植物自己保护自己是无关的。

C选项: Correct. 生产在成熟后能保护自己不被杂草所伤害的植物。如果植物在成熟之后可以自己抑制杂草生长,就不需要除草剂了。

D选项:
 生长在一片只生长一种庄稼的区域。本选项和是否有杂草无关。

E选项:
种植这种植物是为了获得它们的种子,不是叶子或根。本选项和是否有杂草无关。

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