182.The earliest Mayan pottery found at Colha, in LACE w:st="on">BelizeLACE>, is about 3,000 years old. Recently, however, 4,500-year-oold stone agricultural implements were unearthed at colha. These implements resemble Mayan stone implements of a much later period, also found at Colha. Moreover, the implements’ designs are strikingly different from the designs of stone implements produced by other cultures known to have inhabited the area in prehistoric times. Therefore, there were surely Mayan settlements in Colha 4,500 years ago.
Which of the following, if true, most seriously weakens the argument?
(A) Ceramic ware is not known to have been used by the Maya to make agricultural implements.
(B) Carbon dating of corn pollen in Colha indicates that agriculture began there around 4,500 years ago.
(C) Archaeological evidence indicates that some of the oldest stone implements found at Colha were used to cut away vegetation after controlled burning of trees to open areas of swampland for cultivation.
(D) Successor cultures at a given site often adopt the style of agricultural implements used by earlier inhabitants of the same site. D
(E) Many religious and social institutions of the Mayan people who inhabited Colha 3,000 years ago relied on a highly developed system of agricultural symbols.
182.
The passage argues that the Maya inhabited Colha 4,500 years ago from the fact that 4,500-year-old stone implements from Colha are like much later stone implements that are known to be Mayan. You are asked to identify the choice that weakens the argument.
Choice D suggests a different explanation for the similarity of the implements: the Maya copied the design from an earlier culture. Choice D therefore weakens the argument that the Maya inhabited Colha 4,500 years ago and is thus the best answer.
Since the argument in choice A is based on the similarity of stone implements of different ages, the lack of ceramic agricultural implements leaves the argument unaffected. Choice B and C provide no information about who was practicing agriculture in Colha 4,500 years ago, so they fail to weaken the argument. In choice E the fact that by 3,000 years ago Mayan culture was deeply rooted in agriculture indicates a history that goes back before that date and does nothing to weaken the argument.
OG的解释看太不懂。
另外，从我现在做题的情况来看，weaken的题错得最多，特别是哪些和自然科学搭界的题，有什么办法提高吗？
谢谢！ | 
