第4题：加拿大太平洋铁路象征什么？

The Canadian Pacific Railway symbolized unity because it connected Canada's provinces from east to west and helped fulfill the promise made to British Columbia when it joined Confederation.

加拿大太平洋铁路象征加拿大的统一，因为它连接了东西部省份，并兑现了不列颠哥伦比亚省加入联邦时的承诺。