GRE Reading Comprehension: OG/PP2-GRE阅读OG/PP2 - 428F212W4C884EBAP

According to the passage, which of the following is a widely held belief about geese? A. They are not often seen grazing in coastal salt marshes. B. They are not the primary consumers in salt-marsh ecosystems. C. They play only a minor role in the productivity of salt-marsh ecosystems. D. They are the primary determinants of which resources will thrive in coastal salt marshes. E. They control the productivity of salt-marsh ecosystems through a bottom-up process.