新GRE逻辑阅读练习题精选.doc
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1、新GRE逻辑阅读练习题精选 逻辑要点在解GRE阅读是是关键,所以大家要多写一些新GRE逻辑阅读练习题,快来一起学习吧,下面就和大家分享,来欣赏一下吧。新GRE逻辑阅读练习题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. Resea
2、rchers 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 v
3、arying 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 t
4、race 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 th
5、e 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 suita
6、ble 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 i
7、deal 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
8、 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 p
9、ossibly 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 a45 single copper-ore source.While some of
10、 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 t
11、he archaeological record of the Bronze Age.(473 words)4. The author first mentions the addition of flux during smelting in the last sentence in the last paragraph in order to(A) give a reason for the failure of elemental composition studies to determine ore sources(B) illustrate differences between
12、various Bronze Age civilizations(C) show the need for using high smelting temperatures(D) illustrate the uniformity of lead isotope composition(E) explain the success of copper isotope composition analysis For the following question, consider each of the choices separately and select all that apply5
13、. According to the passage, possible sources of the lead found in a copper or bronze artifact include which of the following?A The copper ore used to manufacture the artifactB Flux added during processing of the copper oreC Other metal added during processing of the copper ore6. Select the sentence
14、in the passage that the author rejects copper as the ideal choice.7. It can be inferred from the passage that the use of flux in processing copper ore can alter the lead isotope composition of the resulting metal EXCEPT when(A) there is a smaller concentration of lead in the flux than in the copper
15、ore(B) the concentration of lead in the flux is equivalent to that of the lead in the ore(C) some of the lead in the flux evaporates during processing(D) any lead in the flux has the same isotopic composition as the lead in the ore(E) other metals are added during processing正确答案:4. A 5. ABC 6. Howev
16、er, the variations are large enough 7. D新GRE逻辑阅读练习题Traditional research has confronted only Mexican and United States interpretations of Mexican-American culture. Now we must also examine the culture as we Mexican Americans have experienced it, passing from 5 a sovereign people to compatriots with n
17、ewly arriving settlers to, finally, a conquered peoplea charter minority on our own land. When the Spanish first came to Mexico, they inter-married with and absorbed the culture of the indigenous 10 Indians. This policy of colonization through acculturation was continued when Mexico acquired Texas i
18、n the early 1800s and brought the indigenous Indians into Mexican life and government. In the 1820s, United States citizens migrated to Texas, attracted by land suitable for cotton. 15 As their numbers became more substantial, their policy of acquiring land by subduing native populations began to do
19、minate. The two ideologies clashed repeatedly,culminating in a military conflict that led to victory for the United States. Thus, suddenly deprived of our parent 20 culture, we had to evolve uniquely Mexican-American modes of thought and action in order to survive.(168 words)1. The authors purpose i
20、n writing this passage is primarily to(A) suggest the motives behind Mexican and United States intervention in Texas(B) document certain early objectives of Mexican-American society(C) provide a historical perspective for a new analysis of Mexican-American culture(D) appeal to both Mexican and Unite
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