GRE Reading Comprehension: JiJing 352-GRE阅读机经352篇 - BWS7TZ7H6W2W65EVJ

According to the passage, which of the following statements about bison in the Columbian Basin is true? A. Prior to 1720, bison had no competition for forage. B. The extinction of bison in the Columbia Basin occurred after 1720. C. Bison relied on many of the same food sources as horses did.