GRE阅读考试练习题及答案1

　　The energy contained in rock within the earth’s crust represents a nearly unlimited energy source, but until recently commercial retrieval has been limited to underground hot water and/or steam recovery systems. These systems have been developed in areas of recent volcanic activity, where high rates of heat flow cause visible eruption of water in the form of geysers and hot springs. In other areas, however, hot rock also exists near the surface but there is insufficient water present to produce eruptive phenomena. Thus a potential hot dry rock (HDR) reservoir exists whenever the amount of spontaneously produced geothermal fluid has been judged inadequate for existing commercial systems.

　　As a result of recent energy crisis, new concepts for creating HDR recovery systems—which involve drilling holes and connecting them to artificial reservoirs placed deep within the crust—are being developed. In all attempts to retrieve energy from HDR’s, artificial stimulation will be required to create either sufficient permeability or bounded flow paths to facilitate the removal of heat by circulation of a fluid over the surface of the rock.

　　The HDR resource base is generally defined to included crustal rock that is hotter than 150℃, is at depths less than ten kilometers, and can be drilled with presently available equipment. Although wells deeper than ten kilometers are technically feasible, prevailing economic factors will obviously determine the commercial feasibility of wells at such depths. Rock temperatures as low as 100℃ may be useful for space heating; however, for producing electricity, temperatures greater than 200℃ are desirable.

　　The geothermal gradient, which specifically determines the depth of drilling required to reach a desired temperature, is a major factor in the recoverability of geothermal resources. Temperature gradient maps generated from oil and gas well temperature-depth records kept by the American Association of Petroleum Geologists suggest that tappable high-temperature gradients are distributed all across the United States. (There are many areas, however, for which no temperature gradient records exist.)

　　Indications are that the HDR resource base is very large. If an average geothermal temperature gradient of 22℃ per kilometer of depth is used, a staggering 13,000,000 quadrillion B.T.U.’s of total energy are calculated to be contained in crustal rock to a ten-kilometer depth in the United States. If we conservatively estimate that only about 0.2 percent is recoverable, we find a total of all the coal remaining in the United States. The remaining problem is to balance the economics of deeper, hotter, more costly wells and shallower, cooler, less expensive wells against the value of the final product, electricity and/or heat.

　　21. The primary purpose of the passage is to

　　(A) alert readers to the existence of HDR’s as an available energy source

　　(B) document the challengers that have been surmounted in the effort to recover energy from HDR’s

　　(C) warn the users of coal and oil that HDR’s are not an economically feasible alternative

　　(D) encourage the use of new techniques for the recovery of energy from underground hot water and steam

　　(E) urge consumers to demand quicker development of HDR resources for the production of energy

　　22. The passage would be most likely to appear in a

　　(A) petrological research report focused on the history of temperature-depth records in the United States

　　(B) congressional report urging the conservation of oil and natural gas reserves in the United States

　　(C) technical journal article concerned with the recoverability of newly identified energy sources

　　(D) consumer report describing the extent and accessibility of remaining coal resources

　　(E) pamphlet designed to introduce homeowners to the advantages of HDR space-heating systems

　　23. According the passage, an average geothermal gradient of 22℃ per kilometer of depth can be used to

　　(A) balance the economics of HDR energy retrieval against that of underground hot water or steam recovery systems

　　(B) determine the amount of energy that will used for space heating in the United States

　　(C) provide comparisons between hot water and HDR energy sources in United States

　　(D) revise the estimates on the extent of remaining coal resources in the United States

　　(E) estimate the total HDR resource base in the United States

　　24. It can be inferred from the passage that the availability of temperature-depth records for any specific area in the United States depends primarily on the

　　(A) possibility that HDR’s may be found in that area

　　(B) existence of previous attempts to obtain oil or gas in that area

　　(C) history of successful hot water or steam recovery efforts in that area

　　(D) failure of inhabitants to conserve oil gas reserves in that area

　　(E) use of coal as a substitute for oil or gas in that area

　　25. According to the passage, in all HDR recovery systems fluid will be necessary in order to allow

　　(A) sufficient permeability

　　(B) artificial stimulation

　　(C) drilling of holes

　　(D) construction of reservoirs

　　(E) transfer of heat

　　26. According to the passage, if the average geothermal gradient in an area is 22℃ per kilometer of depth, which of the following can be reliably predicted?

　　I. The temperature at the base of a 10-kilometer well will be sufficient for the production of electricity.

　　II. Drilling of wells deeper than 10 kilometers will be economically feasible.

　　III. Insufficient water is present to produce eruptive phenomena.

　　(A) I only

　　(B) II only

　　(C) I and II only

　　(D) II and III only

　　(E) I, II, and III

　　27. Which of the following would be the most appropriate title for the passage?

　　(A) Energy from Water Sources: The Feasibility of Commercial Systems

　　(B) Geothermal Energy Retrieval: Volcanic Activity and Hot Dry Rocks

　　(C) Energy Underground: Geothermal Sources Give Way to Fossil Fuels

　　(D) Tappable Energy for America’s Future: Hot Dry Rocks

　　(E) High Geothermal Gradients in the United States: Myth or Reality?

　　A C E B E A D

 

GRE阅读考试练习题及答案延伸阅读——gre词汇速记方法

 

　　一、gre词汇初记

　　这个阶段是我们打下词汇基础的过程。我们在这个阶段需要一本涵盖最全面，释义最准确的词汇书，通常我们选择余敏洪所作的《GRE词汇精选》(红宝书)，然后根据自己的或是前人总结的计划(如杨鹏17天)经过一遍到三五遍的词汇记忆，对GRE的词汇有一个初步的印象和记忆。这个阶段结束，我们就已经在词汇这座碉堡上打开了一个突破口。

　　二、gre词汇巩固

　　词汇之所以耗费时间就是因为没有人可以只用一两遍就可以将数万BT单词烂熟于心，而是需要反复的复习和巩固。这个阶段是我们加深词汇在脑海中的印象和初步认识其在题目中应用的过程。

　　三、gre词汇深化

这个阶段不是完全与第二个阶段分开，可以看作是第二阶段的深化过程。这个阶段是在词汇已经熟练到了一定程度的基础上，通过对于词义和用法的进一步精确理解，达到全面掌握已有词汇和增补新词的过程。

　　四、类反实战

全面掌握了词汇不等于能作对题目，如果不经过实战的磨练，我们就会像虚竹一般，空有一身绝世内功却不知如何使用。这个阶段我们要全面投入到真题中，结合前人的优秀解题思路，攻克真题，而这也是我们记忆词汇的最终目的。