PrepTest 150, Section 2, Question 7
Geothermal power plants produce power using heat from(65 more words not shown)
Which one of the following,(9 more words not shown)
- AConventional power plants,(12 more words not shown)
- BA typical geothermal(14 more words not shown)
- CThe high start-up(24 more words not shown)
- DAdvanced drilling technology(25 more words not shown)
- ERecent research has(16 more words not shown)
Reading the argument
What is going to change so that geothermal power can reach most places?
It already works economically where drilling can reach the underground hot water or steam. That sounds promising, but those accessible locations are limited. A good method in a few places doesn't by itself become a widely available method in the near future.
Maybe we'll develop better drills. Maybe we'll get better at locating suitable reservoirs. Or perhaps better transmission will let a plant in one place serve people much farther away. Each possibility points to something that could change availability; none is established just by saying the power is economical where we can already obtain it.
What we’re looking for
The question asks us to strengthen the advocates' prediction. I'd look for evidence of one of those changes, especially a way to overcome the present problem of reaching the heat source without making the power uneconomical.
Working the answers
- A
Less pollution could be a reason to want geothermal power. But wanting it doesn't make the underground resources accessible in more areas. A compares environmental effects without explaining how the predicted expansion becomes possible.
- B
A plant's output doesn't tell us where it can operate. Producing as much power as a conventional plant could be useful once a geothermal plant is built, but the current limitation concerns reaching hot water or steam. B doesn't show that we can build or supply such plants in many more locations.
- C
High initial costs add an obstacle to construction, even where the long-term economics are favorable. That gives us less reason to assume the plants will become widely available soon. It doesn't prove expansion impossible, but it doesn't supply the change that would support the advocates' forecast.
- DCorrect
Here are the better drills I was considering. They will soon let us reach much farther underground, and do so economically. That addresses both the physical obstacle and the cost condition: resources beyond current drilling reach could become usable without losing the economic advantage the prediction depends on. D doesn't prove every area has a suitable reservoir, but it gives a concrete reason availability could expand.
- E
Lower costs can help power production, but the passage identifies a problem of access to the underground resource. Cheaper operation alone doesn't tell us that unreachable hot water or steam will become reachable. And these discoveries apply broadly to power plants, without identifying a change in geothermal access. D is more directly tied to the reason availability is limited now.
More Strengthen questions
Learn the LSAT our way
Our platform drills Strengthen questions at your level and adjusts as you improve.