[单项选择]

In the 18th century, New York was smaller than Philadephia and Boston. Today it is the largest city in America. How to explain the change in its size and importance
To answer this question we must consider certain facts about geography, history and economies. Together these three will explain the huge growth of America’s most famous city.
The map of the Northeast shows that four of the most heavily-populated areas in this region are around seaports. At these points materials from across the sea enter America, and the products of the land are sent there for export across the sea.
Economists know that places where transportation lines meet are good places for making raw materials into completed goods. That is why seaports often have cities nearby. But cities like New York needed more than their geographical location in order to become great industrial centers. Their development did not happen simply by chance.
About 1815,when many Americans fro
A. Because the ships were little crowded on the trip back to New York.
B. Because shipping companies were eager to fill their ships with passengers on the return trip from Europe.
C. Because the shipping companies wanted to develop traveling industry in New York.
D. Because few Europeans longed to visit New York.