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?
答案：17-27:BCDEACEBEAD