PrepTest 108, Section 2, Question 21
The experts who now assure us that genetically(55 more words not shown)
The flawed reasoning in which(14 more words not shown)
- AThe same people(27 more words not shown)
- BThe film critics(34 more words not shown)
- CThe economists who(37 more words not shown)
- DChildren who beg(35 more words not shown)
- EThe population experts(42 more words not shown)
Reading the argument
Being wrong before doesn't make someone wrong every time. These experts recommended introducing non-native plants, and some of those plants became a serious problem. Fair enough: that gives us a reason to be cautious about their next assurance. If they now say genetically engineered plants are harmless, we might want better evidence before trusting them.
But the author goes further. We're supposed to conclude that the plants will be harmful. Why? An unreliable expert can still get something right. “Don't automatically believe them” is a reasonable response to their record. “Believe the opposite of whatever they say” is not.
What we’re looking for
For the parallel flaw, look for that same jump. Someone was wrong about an earlier subject, so the author confidently concludes that the person's current claim is wrong too. The subjects can change; the move from a reason for doubt to a definite rejection must stay.
Working the answers
- A
Nobody is shown to have been wrong before. These people complain about high taxes and insufficient services, and the author draws a conclusion about the connection between taxes and government size. We need a past mistake used to declare a current claim false. The fact that the same people appear twice isn't enough.
- B
The critics were right about the last film. They called it brilliant, and the author agrees that it was excellent. That is the opposite of the past mistake we need.
The author then expects another excellent film despite the critics' current judgment. Perhaps that's a bad reason to dismiss the new reviews, but it isn't “These critics were wrong before, so they're wrong now.”
- CCorrect
The economists failed to predict the end of the recession. That is their earlier mistake. Now they predict that the expansion will end soon, and the author concludes that it will continue instead.
Their track record might justify skepticism. It doesn't establish that this new forecast is false. Just as the plant argument turns past error into certainty that the new plants will be harmful, C turns past error into certainty that the current expansion will continue.
- D
Asking for trendy toys last year isn't a claim that turned out to be false. The author recommends ignoring the children's current requests, but doesn't establish that they previously got something wrong and then use that mistake to reject a new prediction. Repeated requests don't match repeated expert judgments.
- E
The opening fits: these experts made incorrect predictions before. The conclusion goes somewhere different, though. It says that if food shortages occur, the experts' predictions won't be what caused them.
That's a claim about what would cause a shortage, not a conclusion that the shortage forecast is false. E leaves open the possibility that the experts get this prediction right. Our author doesn't leave the current claim open; the author declares it wrong.
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