GRE General TestAnalytical WritingHard
An environmental scientist argues that a proposed dam construction project will severely harm the local ecosystem by disrupting fish migration patterns. The dam's developers counter that the project includes a state-of-the-art fish ladder designed to allow fish to bypass the dam safely. Which of the following, if true, would most seriously weaken the developers' counter-argument?
- AThe local ecosystem relies on the natural flow variations of the river, which the dam would eliminate.
- BThe fish ladder in the project design has been successfully used in similar rivers with different fish species.
- CThe proposed dam is significantly larger than any other dam in the region with a fish ladder.
- DFish ladders are often costly to maintain and can be ineffective if not properly designed for specific fish species.
Show answer & explanationAnswer & explanation
Correct answer: D. Fish ladders are often costly to maintain and can be ineffective if not properly designed for specific fish species.
The developers' counter-argument relies on the fish ladder's effectiveness. If fish ladders are often ineffective or poorly designed for specific species, it directly undermines the assurance that *this* fish ladder will safely mitigate the harm, thus weakening their entire counter-argument.
Why the other options are wrong
- A. This points to another potential environmental harm of the dam (altering natural flow) but doesn't directly challenge the developers' claim about the *effectiveness of the fish ladder* in mitigating fish migration disruption.
- B. This would strengthen the developers' counter-argument by suggesting the fish ladder is effective, not weaken it.
- C. The size of the dam is a factor, but doesn't inherently mean the fish ladder won't work; it just introduces a variable. It doesn't directly challenge the *effectiveness* of fish ladders in general as much as option B.
Weakening a Counter-Argument
To weaken a counter-argument means to introduce information that diminishes the credibility, relevance, or impact of the opposing claim, making it less effective in refuting the original argument.
- Directly targets the opponent's premise or evidence.
- Can show the counter-argument is flawed, insufficient, or irrelevant.
- Aims to restore strength to the original position by discrediting the opposition.
Memory trick: Weakening a counter is like finding the weak spot in their shield.