VSTEP Reading Mock Test 09

The work of the railroad pioneers in America became the basis for a great surge of railroad building halfway through the nineteenth century that linked the nation together as never before. Railroads eventually became the nation’s number one transportation system, and remained so until the construction of the interstate highway system halfway through the twentieth century. They were of crucial importance in stimulating economic expansion, but their influence reached beyond the economy and was pervasive in American society at large.

By 1804, English as well as American inventors had experimented with steam engines for moving land vehicles. In 1820, John Stevens ran a locomotive and cars around a circular track on his New Jersey estate, which the public saw as an amusing toy. In 1825, after opening a short length of track, the Stockton to Darlington Railroad in England became the first line to carry general traffic. American businesspeople, especially those in the Atlantic coastal region who looked for better communication with the West, quickly became interested in the English experiment. The first company in America to begin actual operations was the Baltimore and Ohio, which opened a thirteen-mile length of track in 1830. It used a team of horses to pull a train of passenger carriages and freight wagons along the track. Steam locomotive power did not come into regular service until two years later.

However, for the first decade or more, there was not yet a true railroad system. Even the longest of the lines was relatively short in the 1830s, and most of them served simply to connect water routes to each other, not to link one railroad to another. Even when two lines did connect, the tracks often differed in width, so cars from one line could not fit onto tracks of the next line. Schedules were unreliable and wrecks were frequent. Significantly, however, some important developments during the 1830s and 1840s included the introduction of heavier iron rails, more flexible and powerful locomotives, and passenger cars were redesigned to become more stable, comfortable, and larger. By the end of 1830 only 23 miles of track had been laid in the country. But by 1836, more than 1,000 miles of track had been laid in eleven states, and within the decade, almost 3,000 miles had been constructed. By that early age, the United States had already surpassed Great Britain in railroad construction, and particularly from the mid-1860s, the late nineteenth century belonged to the railroads.

The Asian migration hypothesis is today supported by most of the scientific evidence. The first “hard” data linking American Indians with Asians appeared in the 1980s with the finding that Indians and northeast Asians share a common and distinctive pattern in the arrangement of the teeth. But perhaps the most compelling support for the hypothesis comes from genetic research. Studies comparing the DNA variation of populations around the world consistently demonstrate the close genetic relationship of the two populations, and recently geneticists studying a virus sequestered in the kidneys of all humans found that the strain of virus carried by Navajos and Japanese is nearly identical, while that carried by Europeans and Africans is quite different.

The migration could have begun over a land bridge connecting the continents. During the last Ice Age 70,000 to 10,000 years ago, huge glaciers locked up massive volumes of water and sea levels were as much as 300 feet lower than today. Asia and North America were joined by a huge subcontinent of ice-free, treeless grassland, 750 miles wide. Geologists have named this area Beringia, from the Bering Straits. Summers there were warm; winters were cold, dry, and almost snow-free. This was a perfect environment for large mammals—mammoth and mastodon, bison, horse, reindeer, camel, and saiga (a goatlike antelope). Small bands of Stone Age hunter-gatherers were attracted by these animal populations, which provided them not only with food but with hides for clothing and shelter, dung for fuel, and bones for tools and weapons. Accompanied by a husky-like species of dog, hunting bands gradually moved as far east as the Yukon River basin of northern Canada, where field excavations have uncovered the fossilized jawbones of several dogs and bone tools estimated to be about 27,000 years old.

Other evidence suggests that the migration from Asia began about 30,000 years ago, around the same time that Japan and Scandinavia were being settled. This evidence is based on blood type. The vast majority of modern Native Americans have type O blood and a few have type A, but almost none have type B. Because modern Asian populations include all three blood types, however, the migrations must have begun before the evolution of type B, which geneticists believe occurred about 30,000 years ago.

By 25,000 years ago human communities were established in western Beringia, which is present-day Alaska. But access to the south was blocked by a huge glacial sheet covering much of what is today Canada. How did the hunters get over those 2,000 miles of deep ice? The argument is that the climate began to warm with the passing of the Ice Age, and about 13,000 B.C.E. glacial melting created an ice-free corridor along the eastern front range of the Rocky Mountains. Soon hunters of big game had reached the Great Plains.

Learning means acquiring knowledge or developing the ability to perform new behaviors. It is common to think of learning as something that takes place in school, but much of human learning occurs outside the classroom, and people continue to learn throughout their lives.

Even before they enter school, young children learn to walk, to talk, and to use their hands to manipulate toys, food, and other objects. They use all of their senses to learn about the sights, sounds, tastes, and smells in their environments. They learn how to interact with their parents, siblings, friends, and other people important to their world. When they enter school, children learn basic academic subjects such as reading, writing, and mathematics. They also continue to learn a great deal outside the classroom. They learn which behaviors are likely to be rewarded and which are likely to be punished. They learn social skills for interacting with other children. After they finish school, people must learn to adapt to the many major changes that affect their lives, such as getting married, raising children, and finding and keeping a job.

Because learning continues throughout our lives and affects almost everything we do, the study of learning is important in many different fields. Teachers need to understand the best ways to educate children. Psychologists, social workers, criminologists, and other human-service workers need to understand how certain experiences change people’s behaviors. Employers, politicians, and advertisers make use of the principles of learning to influence the behavior of workers, voters, and consumers.

Learning is closely related to memory, which is the storage of information in the brain. Psychologists who study memory are interested in how the brain stores knowledge, where this storage takes place, and how the brain later retrieves knowledge when we need it. In contrast, psychologists who study learning are more interested in behavior and how behavior changes as a result of a person’s experiences.

There are many forms of learning, ranging from simple to complex. Simple forms of learning involve a single stimulus. A stimulus is anything perceptible to the senses, such as a sight, sound, smell, touch, or taste. In a form of learning known as classical conditioning, people learn to associate two stimuli that occur in sequence, such as lightning followed by thunder. In operant conditioning, people learn by forming an association between a behavior and its consequences (reward or punishment). People and animals can also learn by observation—that is, by watching others perform behaviors. More complex forms of learning include learning languages, concepts, and motor skills.