Directions: There are 3 passages in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A, B, C and D. You should decide on the best choice and put it in the Answer Sheet.

Passage Two

Although the Constitution organized the American states into what was then the largest free-trade zone in the world, geographical constraints sorely inhibited trade and commerce. Enormous physical obstacles and great distances divided the republic. Henry Adams wrote, “No civilized country had yet been required to deal with physical difficulties so serious, nor did experience warrant the conviction that such difficulties could be overcome.” From colonial times to the beginning of the 19th century, the movement of goods from the places of the production to the points of sale continued to be a major problem for merchants and consumers alike. Throughout much of the nation, goods were transported by water from coastal port to coastal port and along navigable rivers and streams. Some freight moved over primitive, rutted（有车辙的） roads, but in many areas the absence of roads meant that commodities could be transported only by pack horse. The cost of shipping items in such fashion often exceeded their value. Conditions for travelers were equally as bad. A 5-day trip north from Philadelphia would take a traveler only as far as Connecticut.

The political and economic leaders of the country recognized the obstacles to commerce that distance and geographical barriers presented. Entrepreneurs and politicians proposed many internal development schemes to improve transportation. In most instances these involved local and state improvements, and the projects called invariably for the expenditure of substantial amounts of capital.