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CR PROBLEM - Q5

Expert replies
by confuse mind » Mon Aug 13, 2012 6:10 pm
The ancient Romans understood the principles of water power very well and in some outlying parts of their empire they made extensive and excellent use of water as an energy sources. This makes it all the more striking that the Romans made do without water power in dominated by large cities.
Which one of the following, if true, contributes most to an explanation of the difference described above in the Romans use of water power?
(A) The ancient Romans were adept at constructing and maintaining aqueducts that could carry quantities of water sufficient to supply large cities over considerable distances
(B) In the areas in which water power was not used water flow in rivers and streams was substantial throughout the year but nevertheless exhibited some seasonal variation
(C) Water power was relatively vulnerable to sabotage but any damage could be quickly and inexpensively repaired
(D) In most areas to which the use of water power was not extended other more traditional sources of energy continued to be used
(E) In heavily populated areas the introduction of water power would have been certain to cause social unrest by depriving large numbers of people of their livelihood


IMO - D OA - E
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Source: — Critical Reasoning |

by alex.gellatly » Mon Aug 13, 2012 7:39 pm
confuse mind wrote:The ancient Romans understood the principles of water power very well and in some outlying parts of their empire they made extensive and excellent use of water as an energy sources. This makes it all the more striking that the Romans made do without water power in dominated by large cities.
Which one of the following, if true, contributes most to an explanation of the difference described above in the Romans use of water power? OK, our job is to find a reason why the Romans, who were very good at using water power, did not use water power in the cities. Obviously the could use water power in the cities because they did so in the outlying areas. So, why didn't the use it in the cities? Perhaps the geography was bad in the cities, it was too expensive, or people would lose their houses due to development. Let look at the answers.
(A) The ancient Romans were adept at constructing and maintaining aqueducts that could carry quantities of water sufficient to supply large cities over considerable distances If they could do this, why not build in the city? Doesn't answer our question.
(B) In the areas in which water power was not used water flow in rivers and streams was substantial throughout the year but nevertheless exhibited some seasonal variation This kind of answer the question, if and only if, every major city and a river. However, the statement still says SEASONAL VARIATION. Obviously constructing water projects would still be advantageous.
(C) Water power was relatively vulnerable to sabotage but any damage could be quickly and inexpensively repaired Again, this kind of answer the question. But, it says the could quickly be repaired. It would still be advantageous to build the projects.
(D) In most areas to which the use of water power was not extended other more traditional sources of energy continued to be used Although this states the source of energy, it does not give a reason why they did this. Obviously the traditional way was not as efficient as the new way (or why would they do so in outlying areas?). This does not give a reason why, rather it just states what they used instead.
(E) In heavily populated areas the introduction of water power would have been certain to cause social unrest by depriving large numbers of people of their livelihood This clearly gives a reason why they wouldn't build such projects. Why would a government build projects if it would lead to social unrest? This is a very powerful reason for the government not to construct water projects in the large cities.
The correct answer is E
A useful website I found that has every quant OG video explanation:

https://www.beatthegmat.com/useful-websi ... tml#475231
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