2010年12月英语六级听力练习三十一

In the early 19th century, it was thought that canals, in which boats and barges were pulled by mules trudging along an adjacent towpath, _____________________________. One, the Erie Canal opened the West to commerce by connecting New York's Hudson River with the Great Lakes in the heartland. It made its backers rich.

Financiers in the Washington, D.C. area also knew what canals meant to cities like Venice in Italy and Tsaritsyn, later called Stalingrad and Volgograd, in Russia. So they hurried to build a new Chesapeake&Ohio Canal from the old port of Georgetown in Washington to Pittsburgh in western Pennsylvania.

The Potomac River flows from Georgetown into the Chesapeake Bay, and Pittsburgh is on the Ohio River. Hence the Chesapeake&Ohio name.The portion along the Potomac, _____________________________, was completed to Cumberland in western Maryland in 1850. It provided a calm, safe route west alongside the river, which is nearly dry upstream part of the year but whose rapids rage in springtime. _____________________________, narrow boats carried cargo on the canal. Mule stables dotted the route.