A．It was built by the Canadians．
B．It was built to facilitate trade．
C．The path for the road was extremely difficult to clear．
D．Hostilities between Canada and the US caused construction delays．

A．Because Canada was influenced by the French government．
B．Because Canada had poor crops and lacked employment．
C．Because Canada was politically turbulent．
D．Because Canada had a bad climate．

A．Because they shared one road．
B．Because there wasn't a border post．
C．Because of the strong French influence．
D．Because immigration went in both directions．