A species that is harmless at home can be ruinous somewhere else, and the reason is usually absence rather than presence. In its native range a plant or animal is held in check by the diseases, predators, and competitors it evolved alongside. Moved to a new continent without them, the same organism may spread at a rate it never managed at home. This is why control programmes so often begin by looking for a natural enemy from the original range, and why that step is approached with great caution. The history of such introductions includes several that became worse problems than the species they were meant to control.
The passage is organized primarily by
Pick an answer
Correct!
Not quite. The correct answer is highlighted.
Correct answer to question 55 (Paragraph Comprehension): stating a principle, explaining it, then noting a risk it creates
Method
It opens with the claim that absence rather than presence explains the damage, spends two sentences on the mechanism, and closes on the caution that follows. No species is named and no solution is rejected outright.
Updated: November 2026
Raise your AFQT scoreFree for iPhone and Android
