托福阅读

❓ 题目 According to the passage, which of the following best illustrates the concept of hysteresis in ecological systems?

A. A. A forest regrows to its original composition after a fire, following a predictable succession path.
B. B. A lake remains turbid even after nutrient inputs are reduced, because the algae-dominated state is reinforced by internal feedbacks.
C. C. A grassland shifts to a shrubland when grazing pressure increases, but returns to grassland once grazing is controlled.
D. D. A coral reef recovers quickly from bleaching if water temperatures return to normal within a few weeks.

B. A lake remains turbid even after nutrient inputs are reduced, because the algae-dominated state is reinforced by internal feedbacks.