阅读课堂笔记范文仅供参考，自行编辑使用阅读课堂笔记A rapid means of long-distance transportation became a necessity for the United States as settlement spread ever farther westward. The early trains were impractical curiosities, and for a long time the railroad companies met with troublesome mechanical problems. The most serious ones were the construction of rails able to bear the load, and the development of a safe, effective stopping system. Once these were solved, the railroad was established as the best m
