Self Check Quiz
Millions of salmon return to Bristol Bay in Alaska to spawn each July. Hundreds of fishermen with boats and long nets wait for them. To ensure that there will be future generations of salmon, the Alaska Department of Fish and Game (ADFG) monitors the fishing ground and sets limits on when and where the fishermen can fish. The ADFG has drawn two boundary lines in the water, one at each end of the bay. The ADFG imposes heavy fines on fishermen who fish outside those boundary lines.
Fishermen cannot see the lines with their eyes. They know, however, where the lines are. They use Global Positioning System (GPS) receivers to monitor their positions, allowing them to stay within the limits set by the Alaska Department of Fish and Game.
The Global Positioning System consists of three elements: the satellites, receivers, and ground stations. There are 24 satellites in fixed orbit around the earth. Over 11 nautical miles out in space, these giant "eyes in the sky" complete an orbit of the earth every 12 hours. The satellites transmit data at the speed of light continually, regardless of weather conditions, to the receivers.
Receivers, located anywhere on Earth, receive signals from at least six satellites at any one time. Even though the satellites send these signals at the speed of light, it still takes a measurable amount of time for the signals to reach the receivers. To give an accurate reading of a location, the receivers first calculate the distance to the satellites by measuring the difference between the time the signal was sent from the satellite and the time it was received, multiplied by the speed of light. Using data received from the satellites, the receiver can determine its exact location on the earth.
Originally developed by the U.S. military, GPS receivers now come in all shapes and sizes; most are the size of a cellular phone. Some are hand-held; others are installed in cars, trucks, ships, and planes. Their job is to receive and decode signals from the satellites and present the results on a screen.
The third element of the GPS is the five large control stations and many unmanned ground stations located around the world. Their job is to stay in constant contact with the satellites. They track their courses and monitor their output.
How do fisherman determine where they can fish in Bristol Bay?
The Alaska Department of Fish and Game drew lines in the water
Fishermen use landmarks to determine the boundaries
They are unsure and risk penalties
Fisherman use GSP systems to determine where they can fish
"A Center of Learning"
In addition to being an important trade location, Timbuktu became a center of learning in western Africa. The rulers of Timbuktu became Muslims, followers of the religion Islam. Muslims believe in education, because they believe that Muslims should be able to read the Quran, the book of Muslim teachings. Many Muslim traders came to live in Timbuktu. They brought their love of learning with them. The city became known for its teachers and libraries. One visitor wrote that "Here are a great store of doctors, judges, priests, and other learned men, that are bountifully maintained at the king's cost and charges. And hither are brought many manuscripts of written books…which are sold for more money than any other merchandise.…"
Timbuktu was a great city for hundreds of years. However, the riches of the area attracted many invaders. Shortly before the year 1600, an army from Morocco attacked. Over a period of many years, the area around Timbuktu was ruled by several different countries. Trade was broken up by wars, and the gold mines of Wangara ran out. Timbuktu once again became a poor village.
The salt mines at Taghaza still produce salt for the people of West Africa. People come on camels and in jeeps to buy the salt, but the importance of the location of Taghaza has changed. No longer is it a stop on a trade route linking Europe with Timbuktu. No longer does gold from Timbuktu flow through Taghaza on its way to trade for goods from Europe.
Timbuktu is no longer a center of world trade and learning. Although its physical location has not changed, the importance of its location has changed.
What is the main idea of this passage?
Timbuktu was an important trade location
Timbuktu was a learning center
Timbuktu was largely unknown
Timbuktu had a shortage of educated people
Every day each of us interacts with people around the world, even though we may not realize it. When you wake up in the morning and punch your pillow before going back to sleep, you may be touching cloth made from cotton grown in Egypt. Your breakfast may include bananas from Latin America. Your ride to school or work may take place in a car from Japan, Germany, or South Korea. Even if the car was made in the United States, chances are that it was put together in Canada. Your jeans may have been sewn in Mexico.
Transportation—the movement of goods and people—makes our interaction with people around the world possible. Imagine how different your life would be if the only goods you could buy were ones produced within your immediate area. Imagine how you would feel if you had to live out your life without ever traveling more than a few miles from where you were born.
Geographers study how people shape the earth's surface. They examine how people move from place to place, how they settle the earth, and how they form societies. Although the human population is scattered unevenly across the earth, we all interact with each other. Some people travel from place to place. Others talk to people around the world by telephone, mail, and e-mail. The Internet, radio, television, and books spread different ideas and ways of life.
Goods and services are also exchanged around the world. Some of the clothes we wear come from other countries. In turn, we send other countries things they need that we produce.
In short, we need other countries, and they need us. No country in the world today can survive strictly on its own. The word we use to describe this relationship is interdependence.
What does interdependence mean?
Each country has resources needed by other countries
Each country operates effectively and independently of other countries
Poor countries rely on wealthy countries for all their goods
Wealthy countries rely on poor countries to provide inexpensive labor
"Leonardo da Vinci"
The Italian Leonardo da Vinci is considered one of the greatest artists of the Renaissance. He painted the Mona Lisa and the Last Supper, two of the world's best-known paintings. He was also a talented architect, engineer, and inventor.
Leonardo da Vinci was born in 1452 in a small town near Florence, Italy. As the son of a wealthy man, he received the best education that Florence could offer. Leonardo became known for his ability to create sculptures and paintings that looked almost lifelike. Much of his success in this area came from his keen interest in nature. He also studied human anatomy and used this knowledge to make his figures realistic.
As a child, Leonardo was fascinated with machines and began to draw his own inventions. The first successful parachute jump was made from the top of a French tower in 1783—but Leonardo had sketched a parachute in 1485. He designed flying machines, armored tanks, and aircraft landing gear. He even drew a diver's suit that used tubes and air chambers to allow a swimmer to remain underwater for long periods of time.
Much of what we know about Leonardo comes from the thousands of pages of notes and sketches he kept in his notebooks. He used mirror, or reverse, writing, starting at the right side of the page and moving across to the left. No one is sure why Leonardo wrote this way. Some think he was trying to keep people from reading and stealing his ideas. He may also have been trying to hide his thoughts from the Roman Catholic Church, whose teaching sometimes conflicted with his ideas. From a practical standpoint, writing in reverse probably helped him avoid smearing wet ink, since he was left-handed.
Which of the following paintings is da Vinci most famous for?
The Last Supper
"Importance of Distance and Relative Location"
Have you ever been lost? Or have you just not been sure about how to get somewhere you wanted to go?
From the specific spot where you stand on Earth, you are different directions and distances from any other spots on Earth. You may be 22 miles south of your home. At the same time, you may be 150 miles northeast of the capital of your state. You may also be three feet from the front door of your favorite pizza place. Your location can, in fact, be compared to the location of any spot on Earth. This is called relative location.
Distance and location affect your life in many ways. If you live eight miles from school, you must wake up earlier each morning than someone who lives eight blocks away. If you live 2,500 miles from the nearest volcano, you will be much less concerned about the latest eruption than someone who lives in the valley below it.
The story of Houston, Texas, is an example of the importance of distance and relative location. One of the greatest oil strikes in history took place near Houston in 1901. The Spindletop Field was the first great oil discovery in Texas. Within a few years Houston was an important center for the oil industry. Why? Because Houston's relative location was near the early oil fields. It was also located near the Gulf of Mexico. This made it possible to ship oil and equipment by water. Many oil companies built plants near Houston to make products from oil. These products were then shipped to other parts of the country and around the world by water. As a result, Houston became one of the largest ports in the United States.
What is your relative location to home?
it depends on where I am now, the direction, and the distance to my home
Stonehenge, one of the world's best-known and most puzzling ancient monuments, stands in southern England.
The most noticeable part of Stonehenge is its huge stones set up in four circular patterns. A circular ditch and mound form a border around the site. Shallow holes in the dirt also circle the stones.
Stonehenge was built over a period of more than 2000 years. The earliest construction, that of the circular ditch and mound, probably began about 3100 B.C. The outer ring of large pillars, topped with horizontal rocks, was built about 2000 B.C. An inner ring of stone pillars also supports horizontal stones.
There was no local source of stone, so workers carried it from an area that was about 20 miles north. The stones are huge—up to 30 feet long and 50 tons in weight. Before setting the stones in place, workers smoothed and shaped them. They carved joints into the stones so that they would fit together perfectly. Then the builders probably used levers and wooden supports to raise the blocks into position.
About 500 years later, builders added the third and fourth rings of stones. This time they used bluestone, which an earlier group of people had transported 240 miles from the Presili Mountains of Wales.
Although much is known about when people built Stonehenge, experts do not agree who built it. Early theories suggested that either an ancient group known as Druids or the Romans built the monument. Now archaeologists believe that the monument was completed long before either of these groups came to the area.
An even greater mystery is why Stonehenge was built. Most experts agree that Stonehenge was probably used as a place of worship. Some believe that the series of holes, stones, and archways were used as a calendar. By lining up particular holes and stones, people could note the summer and winter solstices. They could also keep track of the months. Some scientists think that early people used the site to predict solar and lunar eclipses.
What is the most notable feature of Stonehenge?
the circular ditch forming a border around the site
shallow holes in the dirt which circle the site
the large, elaborate center established for tourists
the huge stones set up in four circular patterns
It was late in the afternoon. Master was not painting, but sitting at his desk making out some accounts and writing to order special pigments from Flanders. The door of the studio opened quietly and His Majesty stepped in, looking around in his uncertain, apologetic way. He was dressed for some court ceremony: black velvet shoes and long black silk stockings, black velvet trousers, but instead of a doublet he wore only a white shirt of thin cotton, and a dressing gown of dark silk brocade. I supposed that after contemplating a picture he meant to return to his rooms, put on his doublet, call the barber to shave him and curl his hair and mustache, and then attach is big white starched ruff at the last moment.
He pulled out his chair, sat, and stretched his long legs with a deep sigh. He smiled amiably at Master, who smiled warmly, affectionately, and then went on with his accounts.
After a short time the King rose and went toward the wall. He stood hesitating a moment, and then turned a canvas toward him. It was mine. In the late light the faithful hounds shone out from the dark background, sunlight on their glistening hides, light in their big, living eyes. His Majesty stood transfixed; he had never seen that canvas before. I could watch his always-slow mind adjusting to the fact that this was a portrait of his own favorite hounds.
I threw myself on my knees before him.
"I beg mercy, Sire," I pleaded. "The painting is mine. I have been working secretly all these years, with bits of canvas and color, copying the works of Master, to learn from them, and trying some original subjects by myself. I know very well that this is against the law. Master has never even suspected and has had nothing to do with my treachery. I am willing to endure whatever punishment you mete out to me."
I remained on my knees, begging the Virgin to remember my promise, praying and asking her forgiveness and her help. Opening my eyes, I saw the feet of His Majesty moving nervously about. Evidently he did not know what to reply. Then he cleared his throat and took a deep breath. The feet in the velvet shoes remained quiet.
"What…What shall we do…with this…this…disobedient slave?" I heard his voice lisping and stuttering, as he turned toward Master.
Still on my knees, I saw Master's neat small feet, in their shoes of Cordovan leather, approach and place themselves in front of my picture. He studied it some time in silence, and the King waited.
Then Master spoke. "Have I your Majesty's leave to write an urgent letter before I answer?"
"You have it."
Master returned to his desk and I heard his quill scratching against the paper. His Majesty returned to his chair and threw himself into it. I remained where I was, praying with all my might. Master rose, and his feet moved toward me.
"Get up, Juan," he said. He put a hand under my elbow and helped me to my feet. He was looking at me with the gentle affection he had always shown me. He took my hand and put a letter into it. I have warn that letter sewed into a silk envelop and pinned inside my shirt ever since. The letter said:
To Whom It May Concern
I have this day given freedom to my slave Juan de Pareja, who shall have all the rights and honors of a free man, and further, I hereby name him my Assistant, with duties and salary thereto pertaining.
DIEGO RODÍGUEZ DE SILVA Y VELÁZQUEZ
Master took the letter gently from my hand, after I had read it, and took it to the King who, reading, smiled radiantly. It was the first time in all those years that I had seen His Majesty smile. His teeth were small and uneven, but that smile seemed to me as beautiful as any I had ever known.
The first paragraph of "Freedom" refers to a brocade. What is a brocade?
a white ruff that attaches to a shirt
a type of woven fabric
dye used in paints
"Russia's Strategy: Freeze Your Foes"
Winter weather can cancel school, bring flu outbreaks, and stop traffic. It can even change history. Such was the case when French ruler Napoleon thought he had conquered the Russian Empire.
In fact, Napoleon did not want to conquer Russia. His real enemy was Great Britain. Napoleon wanted Russia and other countries to stop trading with Great Britain. Yet Russia's czar, Alexander I, refused. By 1812, Napoleon was determined to change Alexander's mind. In June, leading an army of more than half a million soldiers, Napoleon invaded Russia. To reach Moscow and the czar, Napoleon had to fight his way across the Russian countryside.
By the time Napoleon's battle-weary forces reached Moscow, supplies were scarce. All along the route, Russians had burned villages as they retreated, leaving no food or shelter. Reaching Moscow, Napoleon found the city in flames and nearly empty of people. The czar had moved to St. Petersburg. Napoleon took Moscow without a fight, but most of the city was in ashes.
With winter approaching, Napoleon waited in Moscow for Alexander I to offer peace. The czar remained silent, however. With dwindling supplies and many of his troops lacking winter clothes, Napoleon was forced to retreat. He tried to take a new way back, but the Russians made Napoleon use the same ruined route he had used before. Armed bands of Russians attacked at every turn. Most of Napoleon's troops never made it out of Russia.
More than a century later, during World War II, Russia's winter was again a mighty foe. On June 22, 1941, Adolf Hitler's German army invaded Russia, then part of the Soviet Union. As the German army fought its way to Moscow, Soviet leader Joseph Stalin issued his own "scorched-earth policy." Soviet citizens burned anything of use to the invaders. By December, German troops were within sight of the Kremlin, Moscow's government center, when winter struck.
Snow buried the invaders. Temperatures fell below freezing. Grease in guns and oil in vehicles froze solid. German soldiers suffered frostbite and died. The Soviets were better clothed and had winterized their tanks and trucks. Stalin's troops pushed back the German army. Once again the Russians triumphed with help from "General Winter."
What country is Napoleon from?
"The Triangular Trade"
The early history of the United States provides an example of how trade works. In the eighteenth century the land we know as the United States was ruled by England. The land was rich in raw materials such as fish, lumber, and cotton. England also ruled the islands in the West Indies, located southeast of the United States. Large plantations, or farms, on these islands grew sugarcane. Countries ruled by the English had to buy all their manufactured goods from England.
Trade between England and the lands it ruled worked in this way. Ships from New England, in the northeastern part of what is now the United States, carried fish from the region to the West Indies. There the fish was sold to feed the enslaved Africans who worked on the sugar plantations. Farmers paid for the fish with sugar from their crops. Ships then took the sugar to England where it was sold or traded for manufactured goods. The manufactured goods were then taken back to New England and sold. The money from the sale of manufactured goods was used to buy more fish. This was called the triangular trade because the ships moved in a triangle from New England, to the West Indies, to England, and back to New England, where the process began again. The triangular trade worked in another way, too. It would begin in New England, whose fish was taken to the West Indies and traded for sugar. Then the sugar was taken back to New England where it was made into rum. The run was taken to West Africa's Gold Coast. There it was traded for enslaved Africans. The enslaved Africans were then taken to the West Indies and sold to the sugar plantations.
The triangular trade had centers and pathways. The centers were the cities of New England, the West Indies, and England where goods were bought and sold. The pathways were the routes the ships followed across the ocean. The triangular trade also had hinterlands, or areas where raw materials were grown or gathered.
What type of raw material was available in the United States?
Imagine that you are walking through a dense forest of huge trees. The forest is so dense that you need a flashlight to see where you are going. As you look up into the trees, you see different kinds of animals—animals you have never seen anywhere else. Most likely you are walking through one of the world's rain forests.
A rain forest is made up of tall trees that grow year-round in places that have a tropical climate. Tropical rain forests make up only about 7 percent of the earth's surface. However, more than half of the earth's plant and animal species live there. There are more varieties of amphibians, birds, and insects in rain forests than anywhere else in the world.
Rain forests are home to millions of people. Many groups of people have lived in the world's rain forests for thousands of years. It is estimated that as many as 1,000 different cultures may be living in the world's rain forests. Groups such as the Yanomami in South America and the Mbuti of central Africa make a living in the rain forests by hunting, fishing, and gathering forest products.
Rain forests also provide many benefits to people living outside of the rain forests. Wood is one of the most important forest products. Teak, rosewood, and mahogany are used to make furniture around the world. Other products that are made from rain forest plants include tires and toys (from rubber trees), chocolate, cocoa, and cocoa butter (cacoa beans), and chewing gum (sapodilla tree). Other important resources include petroleum and natural gas. Deposits of these resources in Southeast Asia, central Africa, and South America attract foreign businesses.
Rain forests provide scientific value. Scientists believe they have discovered only a small percentage of the plants that grow in the rain forests. Many of these plants have been used to make medicines. For example, specialized medicines used to treat a rare form of leukemia were created from plants in Madagascar's rain forest. Scientists believe that the drugs already in use are just a fraction of the potential medicines rain forests may hold.
Rain forests help to regulate and maintain the environment. They absorb a large amount of rain. Much of the rain evaporates from the leaves of the trees and goes back into the atmosphere as water vapor. Eventually the vapor condenses and comes back to the earth as rain. The thick vegetation of the rain forests helps prevent soil erosion. The plants also absorb carbon dioxide from the atmosphere and give off oxygen. In fact, tropical rain forests absorb more carbon dioxide than any other ecosystem on Earth. Scientists claim that this lessens the impact of global warming. Rain forests also help to control temperature by absorbing light and heat. By doing so, they help keep tropical climates from becoming too hot or too cool.
Which best describes a rain forest?
trees are short, with plenty of space between them
tall trees, tightly packed, in a cold region
tall trees, tightly packed, in a tropical region