托福考试辅导：名师阅读讲义(4)

　　Pennsylvania's colonial ironmasters forged iron and a revolution that had both industrial and political implications. The colonists in North America wanted the right to the profits gained from their manufacturing. However, England wanted all of the Line colonies' rich ores and raw materials to feed its own factories, and also wanted the (5) colonies to be a market for its finished goods. England passed legislation in 1750 to prohibit colonists from making finished iron products, but by 1771, when entrepreneur Mark Bird established the Hopewell blast furnace in Pennsylvania, iron making had become the backbone of American industry. It also had become one of the major issues that fomented the revolutionary break between England and the British colonies. By the (10) time the War of Independence broke out in 1776, Bird, angered and determined, was manufacturing cannons and shot at Hopewell to be used by the Continental Army.
　　After the war, Hopewell, along with hundreds of other "iron plantations," continued to form the new nation's industrial foundation well into the nineteenth century. The rural landscape became dotted with tall stone pyramids that breathed flames and smoke, (15) charcola-fueled iron furnaces that produced the versatile metal so crucial to the nation's growth. Generations of ironmasters, craftspeople, and workers produced goods during war and peace-—ranging from cannons and shot to domestic items such as cast-iron stoves, pots, and sash weights for windows.
　　The region around Hopewell had everything needed for iron production: a wealth of(20) iron ore near the surface, limestone for removing impurities from the iron, hardwood forests to supply the charcoal used for fuel, rushing water to power the bellows that pumped blasts of air into the furnace fires, and workers to supply the labor. By the 1830's, Hopewell had developed a reputation for producing high quality cast-iron stoves, for which there was a steady market. As Pennsylvania added more links to its (25) transportation system of roads, canals, and railroads, it became easier to ship parts made by Hopewell workers to sites all over the east coast. There they ware assembled into stoves and sold from Rhode Island to Maryland as the "Hopewell stove". By the time the last fires burned out at Hopewell ironworks in 1883, the community had produced some 80,000 cast-iron stoves.
　　5. Pennsylvania was an ideal location for the Hopewell ironworks for all of the following reasons EXCEPT
　　(A) Many workers were available in the area
　　(B) The center of operations of the army was nearby
　　(C) The metal ore was easy to acquire
　　(D) There was an abundance of wood
　　答案：B
　　Under the Earth's topsoil, at various levels, sometimes under a layer of rock, there are deposits of clay. Look at cuts where highways have been built to see exposed clay beds; or look at a construction site, where pockets of clay may be exposed. Rivers also reveal Line clay along their banks, and erosion on a hillside may make clay easily accessible.
　　(5) What is clay made of? The Earth's surface is basically rock, and it is this rock that gradually decomposes into clay. Rain, streams, alternating freezing and thawing, roots of trees and plants forcing their way into cracks, earthquakes, volcanic action, and glaciers—all of these forces slowly break down the Earth's exposed rocky crust into smaller and smaller pieces that eventually become clay.
(10) Rocks are composed of elements and compounds of elements. Feldspar, which is the most abundant mineral on the Earth's surface, is basically made up of the oxides silica and alumina combined with alkalis like potassium and some so-called impurities such as iron. Feldspar is an essential component of granite rocks, and as such it is the basis of clay. When it is wet, clay can be easily shaped to make a variety of useful (15) objects, which can then be fired to varying degrees of hardness and covered with impermeable decorative coatings of glasslike material called glaze. Just as volcanic action, with its intense heat, fuses the elements in certain rocks into a glasslike rock called obsidian, so can we apply heat to earthen materials and change them into a hard, dense material. Different clays need different heat levels to fuse, and some, the low-fire (20) clays, never become nonporous and watertight like highly fired stoneware. Each clay can　stand only a certain amount of heat without losing its shape through sagging or melting.
　　Variations of clay composition and the temperatures at which they are fired account for the differences in texture and appearance between a china teacup and an earthenware flowerpot.
　　2. It can be inferred from the passage that clay is LEAST likely to be plentiful in which of the following areas?
　　(A) in desert sand dunes
　　(B) in forests
　　(C) on hillsides
　　(D) near rivers
　　答案：A