【单选题】Before the mid-1860's, the impact of the railroads in the United States was limited, in the sense that the tracks ended at the Missouri River, approximately the center of the country. At the point the...
A.
The impact of railroads was still limited.
B.
Passengers and freight had to transfer from railroads to other modes of transportation to reach western destinations.
【简答题】第三部分:阅读理解(共20小题;每小题2分,满分40分) Before the mid 1860’s, the impact of the railroads in the United States was limited, in the sense that the tracks ended at this Missouri River, approximately the center of...