求助TPO5一道阅读题

yyyusaUID：3335402

原文：
Paragraph 6: Only recently have investigators considered using these plants to clean up soil and waste sites that have been contaminated by toxic levels of heavy metals–an environmentally friendly approach known as phytoremediation. This scenario begins with the planting of hyperaccumulating species in the target area, such as an abandoned mine or an irrigation pond contaminated by runoff. Toxic minerals would first be absorbed by roots but later relocated to the stem and leaves. A harvest of the shoots would remove the toxic compounds off site to be burned or composted to recover the metal for industrial uses. After several years of cultivation and harvest, the site would be restored at a cost much lower than the price of excavation and reburial, the standard practice for remediation of contaminated soils. For examples, in field trials, the plant alpine pennycress removed zinc and cadmium from soils near a zinc smelter, and Indian mustard, native to Pakistan and India, has been effective in reducing levels of selenium salts by 50 percent in contaminated soils.

问题：

11. It can be inferred from paragraph 6 that compared with standard practices for remediation of contaminated soils, phytoremediation
○does not allow for the use of the removed minerals for industrial purposes
○can be faster to implement
○is equally friendly to the environment
○is less suitable for soils that need to be used within a short period of time

答案选4，依据应该就是原文中红色那句话。但是原文只说phytoremediation需要几年时间，没提standard practices需要多少时间。所以我认为不能说phytoremediation is less suitable for soils that need to be used within a short period of time

black_marbleUID：3257768

这个需要用点排除法吧，第一个是错的 to recover the metal for industrial uses。
第二be faster,这个根本就没提。
第三个equally也没有对比的对象。

我个人觉得是excavation and reburial 这两个是收人工控制的，而phytoremediation这个是收植物控制的，就是它的生长周期控制的，这个如果想快速用这个土地的话没有办法的

yyyusaUID：3335402

black_marble 发表于 2012-8-21 14:48
这个需要用点排除法吧，第一个是错的 to recover the metal for industrial uses。
第二be faster,这个根本 ...

人工控制比植物控制更快虽然有道理，可是原文没有说。所以用排除法的话，4也有理由排除

black_marbleUID：3257768

yyyusa 发表于 2012-8-21 15:27
人工控制比植物控制更快虽然有道理，可是原文没有说。所以用排除法的话，4也有理由排除

这个具体分析确实不是太好确定，要不你看看http://blog.sina.com.cn/s/blog_732869e601012b5l.html
这个里面可能也没法给你满意的答案

yyyusaUID：3335402

谢谢啦。也许就是这道题不好

Aaron_UID：3368803

我试试看这么解释哦 题目要求infer from the paragraph，那么整体来看这一段就是讲了植物如何消化掉污染物，尤其应该注意的是按时间顺序来写消化步骤的，即从种植到吸收到收割到最终移除，那么就不难推测答案一定是与时间相关的了