TOEFL Reading: ETS-TOEFL阅读机经 - D3DX943M53Q1M0H5L$

What can be inferred from paragraph 5 about agricultural production during the nineteenth century A. Irrigation and the use of modern tools contributed little to increased production in comparison with other factors. B. Interior regions increased their agricultural production much more than regions near river basins did. C. Agricultural production was aided by using less-productive land for animal pasture instead of for growing crops. D. Agricultural production increased in some areas but decreased in others during the nineteenth century.