The passage suggests which of the following about the identification of a species as a keystone species?
Which of the following, if true, would most clearly support the argument about keystone status advanced in the last sentence of the passage (in the highlighted text)?
Which of the following hypothetical experiments most clearly exemplifies the method of identifying species' roles that the author considers problematic?
The passage mentions which of the following as a factor that affects the role of P. ochraceus as a keystone species within different habitats?
Which of the following best describes the function of the sentence in the highlighted text?
Which of the following most accurately describes the organization of the passage?
According to the passage, each of the following is true of endangered amphibian species EXCEPT:
It can be inferred from the passage that the author believes which of the following to be true of the amphibian extinctions that have recently been reported?
It can be inferred from the passage that the author believes which of the following to be true of the environmentalists mentioned in the highlighted text?
The primary purpose of the passage is to