❓ 質問 According to the passage, why is measuring ecological resilience considered difficult?
- A. A. Because resilience is a purely theoretical concept with no practical applications.
- B. B. Because it requires long-term observation and thresholds are often not apparent until crossed.
- C. C. Because most ecosystems are already in a stable state and do not change over time.
- D. D. Because response diversity is too difficult to quantify in natural environments.