TPO21 一道阅读题Paragraph 5:Like most other energy sources,geothe

TPO21 一道阅读题
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sources,geothermal energy presents some environmental problems.The surface of the ground can sink if hot groundwater is withdrawn without being replaced.In addition,water heated geothermally can contain salts and toxic materials dissolved from the hot rock.These waters present a disposal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?(1)
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.
请问 为什么D不正确 .我知道A正确,但D的说法也对啊,当初就是纠结A、D ,