A-A+
What major development in the 19th century led
问题详情
What major development in the 19th century led to a great economic boom for the cowboy？
A．The cow town settlements.
B．The construction of the railroads.
C．The pioneer settlements.
D．The use of modern technology.
参考答案
正确答案：B
解析：定位句中A great boon to the life of the cowboy与题干中的a great economic boom for the cowboy相对应，联系原文接下来部分可以推测B The construction of the railroads与原文相符，故为答案。
