TOEFL Listening: TPO-TOEFL阅读TPO - 4193M5NKJ54QZN1CN$

Paragraph 4 supports the idea that the price of wheat more than doubled between 1845 and 1855 because A. the price of corn nearly doubled during that same period B. demand for grain increased sharply outside the United States C. farmers in the Northeast and Midwest began to specialize in cash crops D. many farmers had borrowed heavily to purchase land and equipment for raising wheat