【阅读题讨论】36套E12.7

346610045

阅读36套 E12 第7题
7. It can be inferred from the passage thatthe use  
of flux in processing copper ore can alterthe  
lead isotope composition of the resultingmetal  
EXCEPT when
(A) there is a smaller concentration oflead in  
the flux than in the copper ore  
(B) the concentration of lead in the fluxis  
equivalent to that of the lead in theore  
(C) some of the lead in the fluxevaporates  
during processing  
(D) any lead in the flux has the sameisotopic  
composition as the lead in the ore  
(E) other metals are added duringprocessing

答案是D，很多人给的解释是D 有any 太绝对话了，Line45 有some

但如果具体看选项A和B似乎是矛盾的选项， B和D 似乎是相似选项，D只是多了个any.，
所以看似应该选A。【原文也没有仔细翻译，考试也不需要吧，所以现在也不是非常理解文义，如果有人能解释下最好，但撇开理解，纯按照逻辑结构是如何选出D的？】

346610045

贴上原文，此题定位大概在第二段中间开始

The determination of the sources of copper ore used in  
the manufacture of copper and bronze artifacts of Bronze  
Age civilizations would add greatly to our knowledge of  
cultural contacts and trade in that era. Researchers have  
5 analyzed artifacts and ores for their concentrations of elements,  
but for a variety of reasons, these studies have generally failed  
to provide evidence of the sources of the copper used in the  
objects. Elemental composition can vary within the same  
copper-ore lode, usually because of varying admixtures of  
10 other elements, especially iron, lead, zinc, and arsenic. And  
high concentrations of cobalt or zinc, noticed in some artifacts,  
appear in a variety of copper-ore sources. Moreover, the  
processing of ores introduced poorly controlled changes  
in the concentrations of minor and trace elements in the  
15 resulting metal. Some elements evaporate during smelting  
and roasting; different temperatures and processes produce  
different degrees of loss. Finally, flux, which is sometimes  
added during smelting to remove waste material from the  
ore, could add quantities of elements to the final product.  
20 An elemental property that is unchanged through these  
chemical processes is the isotopic composition of each  
metallic element in the ore. Isotopic composition, the  
percentages of the different isotopes of an element in a given  
sample of the element, is therefore particularly suitable as an  
25 indicator of the sources of the ore. Of course, for this purpose  
it is necessary to find an element whose isotopic composition  
is more or less constant throughout a given ore body, but  
varies from one copper ore body to another or, at least, from  
one geographic region to another.  
30 The ideal choice, when isotopic composition is used to  
investigate the source of copper ore, would seem to be copper  
itself. It has been shown that small but measurable variations  
occur naturally in the isotopic composition of copper.  
However, the variations are large enough only in rare  
35 ores; between samples of the common ore minerals of copper,  
isotopic variations greater than the measurement error have  
not been found. An alternative choice is lead, which occurs  
in most copper and bronze artifacts of the Bronze Age in  
amounts consistent with the lead being derived from the  
40 copper ores and possibly from the fluxes. The isotopic  
composition of lead often varies from one source of  
common copper ore to another, with variations exceeding  
the measurement error; and preliminary studies indicate  
virtually uniform isotopic composition of the lead from a  
45 single copper-ore source. While some of the lead found in  
an artifact may have been introduced from flux or when  
other metals were added to the copper ore, lead so added in  
Bronze Age processing would usually have the same isotopic  
composition as the lead in the copper ore. Lead isotope  
50 studies may thus prove useful for interpreting the  
archaeological record of the Bronze Age.