❓ 题目 According to the passage, what is a key implication of Paine's experiment with Pisaster ochraceus?
- A. A. Predators always reduce the total number of species in an ecosystem.
- B. B. A single predator can control the abundance of dominant competitors and thereby maintain diversity.
- C. C. Removing a keystone species has no effect on community structure.
- D. D. Keystone species are always the largest or most abundant organisms.