GRE Reading Comprehension: ETS-GRE阅读ETS - 5RWM9YT2CVCL84HG7

Which one of the following best expresses the main idea of the passage? A. The reduction in biodiversity is an irreversible process that represents a setback both for science and for society as a whole. B. The material and cultural wealth of a nation are insignificant when compared with the country's biological wealth. C. The enormous diversity of life on Earth could not have come about without periodic extinctions that have conferred preeminence on one species at the expense of another. D. The human species is in the process of initiating a massive extinction episode that may make past episodes look minor by comparison. E. The current decline in species diversity is human-induced tragedy of incalculable proportions that has potentially grave consequences for the human species.