Samples from the floor of a rock shelter in Pennsylvania were dated by analyzing the carbon they contained. The dates assigned to samples associated which human activities formed a consistent series, beginning with the present and going back in time, a series that was correlated with the depth from which the samples came. The oldest and deepest sample was dated at 19,650 years before the present, plus or minus 2,400 years. Skeptic, viewing that date of human migration into North America, suggested that the samples could have been contaminated by dissolved "old carbon" carried by percolating groundwater from nearby coal deposits.
Which one of the following considerations, if true, argues most strongly against the suggestion of the skeptics?
(A) No likely mechanism of contamination involving percolating groundwater would have affected the deeper samples from the site without affecting the uppermost sample.
不明白的地方是：skeptic 是怎么得出结论的？为什么说有污染呢？ ＂viewing that date of human migration into North America＂ 就代表两个日期不一样？
（1）因为date of human migration into North America,所以 suggested that the samples could have been contaminated by dissolved "old carbon" carried by percolating groundwater from nearby coal deposits
（2）因为The oldest and deepest sample was dated at 19,650 years before the present，而date of human migration into North America，所以the samples could have been contaminated by dissolved "old carbon" carried by percolating groundwater from nearby coal deposits.
（2）因为The oldest and deepest sample was dated at 19,650 years before the present，而date of human migration into North America，所以the samples could have been contaminated by dissolved "old carbon" carried by percolating groundwater from nearby coal deposits.
＂而date of human migration into North America，＂这是一句话吗？ 我怎么觉得skepic 也没说date of human migration into North America是什么时候？难道date不是名词在这儿？
By the way, you should know why you need to ask these questions rather than get better understanding of the precise content of every aspects of stimulus.Because some parts that you should not have to analysis.
For this question, one can pick out the correct answer by eliminating all other four irrelevant choices. But, without knowing the explicit meaning of the premises and conclusion, it is not easy to get the correct answer by the first glance. And, there is always a high risk of getting the wrong choice in many other situations in lr without knowing exactly what the author is saying. So,..., ....,....., i still want to know.....
好吧~~sevfye老兄~~如果你非要弄明白哩~~Skeptic, [viewing that date of human migration into North America], suggested that…[]就是一个插入的伴随嘛~~也没什么可纠结滴~~ 还有我不得不说~~Crusoe你好萌~~
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发表于 2009-6-27 13:07:00
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我怎么觉得skepic 也没说date of human migration into North America是什么时候？难道date不是名词在这儿？
