O the underground rock must be fractured before heat can be removed from it

　　O the water above the rock is under very high pressure

　　O the rock breaks apart when water is pumped into it

　　O the water circulated through the rock must be much cooler than the rock itself.

　　题型：细节题

　　定位词：extracting heat from very hot, dry rocks is difficult

　　解题思路：本段第一句出现定位词，并说明了从石头中提取热量困难的两个原因：必须在岩石裂隙允许水循环，水必须人工提供。选项A符合第一个原因的说法，为正确选项。

　　重点句子翻译：

Extracting heat from very hot, dry rocks presents a more difficult problem: the rocks must be fractured to permit the circulation of water, and the water must be provided artificially.

　　从非常热、干燥的岩石中提取热量提出了一个更棘手的问题：必须在岩石裂隙允许水循环，水必须人工提供。

　　Paragraph 4：Extracting heat from very hot, dry rocks presents a more difficult problem: the rocks must be fractured to permit the circulation of water, and the water must be provided artificially. The rocks are fractured by water pumped down at very high pressures. Experiments are under way to develop technologies for exploiting this resource.

　　9. The word “ exploiting” in the passage is closest in meaning to

　　O locating

　　O increasing

　　O making use of

　　O estimating the size of

　　题型：词汇题

　　解题思路： 本段前半部分说了从石头中提取热量困难的两个原因，按照正常的思考逻辑，最后一句话是说“发展技术、利用这种自然资源的实验正在开发中”。所以C项正确。

　　Paragraph 5：Like most other energy sources, geothermal energy presents some environmental problems. The surface of the ground can sink if hot groundwater is withdrawn without being replaced. In addition, water heated geothermally can contain salts and toxic materials dissolved from the hot rock. These waters present a disposal problem if they are not returned to the ground from which they were removed.

　　10. How is the problem that the surface may sink related to the problem that water heated geothermally may contain toxic materials?

　　O Both problems could be solved by returning groundwater that is removed from an underground heat reservoir back to the reservoir after heat is extracted from it.

　　O The problem of sinking is more difficult to solve than is the problem of toxic materials.

　　O Land at the surface sinks because the rock beneath the surface is weakened when salts and toxic materials are removed from it in the process of extracting geothermal energy.

　　O Both problems are caused by the fact that the hot groundwater in a heat reservoir dissolves the rock, which weakens the rock and makes the water toxic with salt.

　　题型：细节题

　　定位词： he surface may sink related to the problem that water heated geothermally may contain toxic materials

　　解题思路：根据本段结构，可知定位词中的两种现象都是地热能利用导致的环境问题，最后一句话提到了它们可能的一种解决方式，选项A是最后一句话的同义改写，为正确选项。

　　重点句子翻译：