TOEFL Reading: ETS-TOEFL阅读机经 - E3686NLB5AQ3K3K7L$

Paragraph 5 implies which of the following about the export trade in grain? A. The growth of the export trade caused most custom mills to go out of business. B. The export trade did not have a significant economic impact beyond the large port cities. C. The export trade's use of cash for payments led farmers to produce surpluses for this market. D. In the export trade, most of the profits were made by the primary products and grain brokers