Recently, Smith City replaced all paper-towel dispensers in lavatories of city buildings with electric hand dryers. The city estimates that in about fifteen years the amount that would otherwise have been spent on the purchase and disposal of paper towels would begin to exceed the cost of purchasing, installing, and operating the electric dryers. Therefore, despite high initial costs, replacing paper towels with electric hand dryers will be to the city's long-term economic advantage.
Which of the following is an assumption on which the argument depends?
A The costs of repairing electric hand driers will be the same fifteen years from now as it is today.
B Almost every business in Smith City that has replaced the paper towel dispensers with electric hand dryers has found the replacement to be to its long-term economic advantage.
C The city will not, within ten years, have to replace most of the recently installed electric hand dryers with new dryers.
D The number of electric hand dryers recently installed in Smith City is not significantly greater than the number of paper towel dispensers removed.
E The initial costs involved installing paper towel dispensers is less than that of installing electric hand dryers.
Nitrogen-based crop fertilizers create polluting runoff that causes death zones in bodies of water. Scientists are developing seeds for various crops that use nitrogen more efficiently than regular seeds do, enabling farmers to reduce fertilizers use by twenty to thirty percent and get the same yields as they currently do. However, experts predict that widespread use of new seeds will be unlikely ever to leads to a decrease in nitrogen pollution.
Which of the following would, if true, provide the strongest justification for the experts’ prediction?
A Environmental interventions designed to mitigate the impact of nitrogen pollution of bodies of water have been efficiently implemented over the past decades.
B Seeds that produce drought-resistant crops have been widely adopted by commercial farmers but have not led to a decrease in nitrogen pollution.
C Farmers usually apply fertilizer before planting, when there's no root system to hold it in place , making it more susceptible to run off.
D Farmers who plant the new seeds but use the traditional amount of fertilizer will get greater yields from their land than they currently get.
E The new seeds are unlikely to be available for widespread commercial planting for at least ten to fifteen years.