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Narrative Nonfiction EXPLOR ING THE DEEP BY SUE GIBBISON PAIRED READ Curious About Earth CV_CR14_LR_G6_U1W4L60_O_118642.indd 3 27/01/12 1:52 PM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF STRATEGIES & SKILLS Comprehension Vocabulary Strategy: Reread Skill: Main Idea and Key Details cascaded, documentation, dynamic, exerts, plummeting, pulverize, scalding, shards Vocabulary Strategy Content Standards Metaphor and Simile Science Earth and Space Science Word Count: 2,101** Photography Credit: Cover Ralph White/CORBIS. **The total word count is based on words in the running text and headings only. Numerals and words in captions, labels, diagrams, charts, and sidebars are not included. Copyright © The McGraw-Hill Companies, Inc. All rights reserved. No part of this publication may be reproduced or distributed in any form or by any means, or stored in a database or retrieval system, without the prior written consent of The McGraw-Hill Companies, Inc., including, but not limited to, network storage or transmission, or broadcast for distance learning. Send all inquiries to: McGraw-Hill Education Two Penn Plaza New York, New York 10121 ISBN: 978-0-02-118642-6 MHID: 0-02-118642-1 Printed in the United States. 1 2 3 4 5 6 7 8 9 DOC 15 14 13 12 11 10 A IFCIBC_CR14_LR_G6_U1W4L60_O_118642.indd 2 27/01/12 1:53 PM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF Essential Question How do natural forces affect Earth? EXPLOR ING THE DEEP BY SUE GIBBISON Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Chapter 1 Discoveries of the Deep . . . . . . . . . . . . . . . . . . . . . . 4 Chapter 2 A Remarkable Discovery . . . . . . . . . . . . . . . . . . . . . . 8 Chapter 3 The Missions Continue . . . . . . . . . . . . . . . . . . . . . . . . 12 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Respond to Reading . . . . . . . . . . . . . . . . . . . . . . . . . 18 PAIRED READ Curious About Earth . . . . . . . . . . . . . . . 19 Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 Focus on Science . . . . . . . . . . . . . . . . . . . 24 001_009_CR14_LR_G6_U1W4L60_O_118642.indd 1 7/02/12 11:23 AM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF INTRODUCTION Imagine being in an underwater vehicle, moving slowly through inky-black water. You don’t know what exciting things you’ll find, or what dangers await you. This is the experience of scientists who explore the deep ocean. In the past 50 years, deep-ocean explorers have found a surprising variety of marine life in these extreme conditions. In the deep ocean, there is no light, the water is usually freezing cold, and the pressure is immense. Scientists have also studied the movements of the ocean floor to better understand the dynamic forces beneath Earth’s crust. Exploring such remote places takes skill. Scientists also need help from miniature submarines called human-occupied vehicles (HOVs). A key tool in undersea exploration has been an HOV called Alvin. Since 1964, this helped them to discover new species and study undersea volcanoes. It has even helped them explore the underwater wreck of the Titanic. Ralph White/CORBIS craft has carried scientists on more than 4,500 dives. It has Alvin explores the bottom of the ocean. 2 001_009_CR14_LR_G6_U1W4L60_O_118642.indd 2 7/02/12 11:24 AM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF EMORY KRISTOF/National Geographic Stock Alvin is lowered into the ocean. Alvin can travel to great depths. At such depths, the weight of the ocean exerts huge pressure. Alvin was designed by the Woods Hole Oceanographic Institution to withstand this enormous pressure, which would pulverize a regular submarine. Alvin is transported to each mission on board the research ship Atlantis. The ship is specially built to carry the HOV and launch it for its dives. The work done by scientists on Alvin has helped us to understand the giant forces that move and shape the surface of our planet. 3 001_009_CR14_LR_G6_U1W4L60_O_118642.indd 3 7/02/12 11:24 AM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF CHAPTER 1 DISCOVER IES OF THE DEEP In 1977, Atlantis sailed on a mission. There was a team of scientists on board—along with Alvin. The scientists’ mission was to explore the Galapagos Rift. This is an undersea area off the coast of South America that is volcanically active. EXPLORING TECTONIC PLATES Since the 1960s, scientists have been trying to learn more about how large areas of Earth’s surface, called tectonic plates, move. When tectonic plates move apart, molten rock, which is very hot, is forced up into the space. The molten rock erupts through the ocean floor. It creates undersea mountain ranges called mid-ocean ridges, which force the plates farther apart. This is called Illustration: Carlos Aon “seafloor spreading.” Formation of Mid-ocean Ridges continent mid-ocean ridge tectonic plate continent tectonic plate molten rock 4 001_009_CR14_LR_G6_U1W4L60_O_118642.indd 4 7/02/12 11:24 AM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF The theory that Earth’s surface moves isn’t new. In 1912, a scientist named Alfred Wegener proposed that Earth’s continents were once joined together in a supercontinent. He named this Pangaea (pan-JEE-uh). Over millions of years, he said, the continents had drifted apart. Earth’s Great Jigsaw Puzzle Tectonic plates move and interact in different ways. Sometimes they bump together, sometimes they drift apart, and sometimes they slip past one another. These movements cause earthquakes and volcanic eruptions. Some plates carry continents as well as oceans; others carry just one or the other. For example, the Pacific Plate is an ocean plate that carries the Pacific Ocean. North American Plate Mountain High Maps/Digital Wisdom Pacific Plate Eurasian Plate South American Plate African Plate Australian Plate Antarctic Plate There are seven main tectonic plates. 5 001_009_CR14_LR_G6_U1W4L60_O_118642.indd 5 7/02/12 11:24 AM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF CLAMS AND SHIMMERING WATER In 1977, scientists aboard Alvin were exploring what was actually happening on the ocean floor at the Galapagos Rift. They were interested in exploring seafloor spreading to find out how it affects the oceans. As Alvin reached the ocean floor, its powerful lights lit up the scene. Scientist Jack Corliss found something unexpected. There were hundreds of large clams on a bare ocean floor. Corliss was surprised because he was expecting the ocean floor to be lifeless. By radio, Corliss told a scientist on the support boat, “There are all these animals down here!” Woods Hole Oceanographic Institution The crew was amazed that any life could exist in such a cold and hostile place with absolutely no sunlight. Then, while watching crabs scuttle around, Corliss noticed something even more unusual. He could see shimmering water. Alvin’s operator collected a sample of the clams. Pilot Larry Shumaker was also stunned by what he saw. “I felt like Alice in Wonderland. I remember the shimmering water coming from the vents and the unusual animals that humans had never seen before … At the time it was all so weird and new.” 6 001_009_CR14_LR_G6_U1W4L60_O_118642.indd 6 7/02/12 11:24 AM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF THER MAL VENTS Corliss had spotted a thermal vent. Thermal vents are cracks in the ocean floor where heated water gushes into the cold ocean water. Scientists had thought that thermal vents might occur in undersea volcanic areas, but this was the first time anyone had seen one. So what gave scientists the idea that thermal vents existed? Scientists thought that as the new seafloor formed at the ridges, rocks would split. This would allow seawater to seep into the hotter parts of Earth, where it would heat up. The seawater would then gush back into the ocean like hot water from a giant kettle. Vent Formation mid-ocean ridge vent cold water seeps into rock crack Illustration: Carlos Aon tectonic plate plate The discovery of thermal vents during the 1977 mission confirmed scientists’ ideas about thermal vents that form at mid-ocean ridges. In later missions, scientists aboard Alvin would make even more dramatic discoveries. 7 001_009_CR14_LR_G6_U1W4L60_O_118642.indd 7 7/02/12 11:24 AM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF CHAPTER 2 A R EM AR K ABLE DISCOVERY In 1979, scientists went on another Alvin mission to explore seafloor spreading and thermal vents. Off the coast of Mexico, the Atlantis reached its destination. Below the ship, the seafloor rose in a gentle slope called the East Pacific Rise. This is a mid-ocean ridge running along the U.S Geological Survey floor of the Pacific Ocean from California to South America. DISCOVERING BLACK SMOKERS The crew of Alvin came across a peculiar sight. Peering through their viewports, they saw what looked like clouds of black smoke. The clouds gushed from the tops of The water gushing from a black smoker can reach temperatures of more than 700 degrees Fahrenheit. miniature smokestacks that seemed to be growing from the ocean floor. In 1977, Jack Corliss had described the thermal vents as looking like shimmering water. These vents were very different and would become known as “black smokers.” 8 001_009_CR14_LR_G6_U1W4L60_O_118642.indd 8 7/02/12 11:24 AM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF Illustration: Carlos Aon Black Smokers Black smoker is the name given to one kind of thermal vent. It’s a tall, cone-shaped chimney that forms on the ocean floor. The black “smoke” that pours out is actually superheated water that is full of dissolved minerals. When this scalding fluid shoots out of the smoker, it hits freezing seawater. The fluid cools instantly, and the metals and minerals in the fluid form tiny black shards. The chimney forms because some of these shards have cascaded down the sides of the smoker. In this way, the smoker’s chimney can grow up to 12 inches a day. Scientists are interested in black smokers because they provide information about the processes that happen deep inside Earth. They are also interested in studying the metals and minerals pumped out by the vents. 9 001_009_CR14_LR_G6_U1W4L60_O_118642.indd 9 7/02/12 11:24 AM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF RETURNING TO THE EAST PACIFIC RISE In 1999, Alvin returned to the East Pacific Rise to explore the seafloor further. After a journey of two and a half hours, Alvin reached the ocean floor. The scientists had just five hours to do their work before traveling back to the surface. Alvin was equipped to help scientists bring back Rod Catanach KRT/Newscom documentation of this unique and dynamic underwater world. Cameras on Alvin’s hull took images. Its two robotic arms gathered pieces of basalt rock and samples of deep-sea life. The equipment on Alvin helps scientists view, photograph, and collect their findings on the seafloor. light camera viewport robotic arm sample basket 10 010_018_CR14_LR_G6_U1W4L60_O_118642.indd 10 10/02/12 3:56 PM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF Scientists also tested the water around thermal vents to find out what chemicals it contained. They were especially The black smoker is now on display in a museum in Wellington, New Zealand. interested in the black smokers. The area around these vents is a unique, extreme habitat. This is because of the heat and the chemicals being pumped out. Bacteria grow around the vents. Strange and unusual creatures, such as giant tube worms and large clams, thrive in this environment. Alvin gathered samples from the vent areas so scientists could study them later. Once, Alvin’s crew accidentally knocked over a black smoker. Operated by a scientist on Alvin, the HOV’s robotic arm reached out and lifted the smoker, and then placed it carefully in the sample basket. Only a handful of black smokers have ever been collected from the seafloor. Cornel de Ronde/GNS Science This was a great finale for the mission. 11 010_018_CR14_LR_G6_U1W4L60_O_118642.indd 11 10/02/12 3:56 PM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF CHAPTER C CHAP CH APTER APT TER R3 THE MISSIONS CONTINUE A diver carries out a final check before the crew takes Alvin to the ocean floor. For more than 50 years, Alvin has played a key role in unlocking the secrets of the deep ocean. Over time, its design has been improved, and it has been given regular overhauls. Almost every nut and bolt on the HOV has now been replaced. Alvin needs to withstand the pressure of the deep ocean, just as space shuttles need to withstand the vacuum of outer space. Each year, the support ship Atlantis takes Alvin to new and already explored areas. To date, its more than 4,500 the wonders of the sunless depths. They have gathered important information on the life there and the huge forces that shape our planet. 12 010_018_CR14_LR_G6_U1W4L60_O_118642.indd 12 Woods Hole Oceanographic Institution dives have allowed hundreds of scientists to experience 10/02/12 3:56 PM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF STUDYING LIFE AROUND THER MAL VENTS In 1977, scientists aboard Alvin discovered the giant clams on the ocean floor. Since then, many other diverse forms of life have been found on and around the vents. The hot water emerging from Earth’s mantle creates a habitat where life thrives without sunlight. Tube worms, giant clams, and long-necked barnacles cluster around thermal vents. These creatures feed on the sugars produced by bacteria that live on and around the vents. The scientists aboard Alvin have gathered many samples that help them understand life in this habitat. National Oceanic and Atmospheric Administration (NOAA) Tube worms never leave their shells. They live on sugar made by the bacteria that live inside the tube worms’ shells. 13 010_018_CR14_LR_G6_U1W4L60_O_118642.indd 13 10/02/12 3:56 PM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF MAKING NEW DISCOVERIES Scientists acquire new knowledge on every mission. In 2002, Atlantis cruised with Alvin back to the Galapagos Rift. Scientists were surprised that tectonic plate activity had dramatically changed the seabed since their visit in 1977. Many marine creatures had been wiped out by fresh lava flowing from the ocean floor. In other places where there had been little life, giant tube worms flourished around new thermal vents. In 2002, Alvin also explored the seafloor in the Gulf of Alaska. Scientists took samples of the rocks from the seafloor. Some of these samples were unusual because they didn’t match the other rocks in the area. This was because icebergs past, rocks that had become embedded in them many years earlier were sent plummeting to the ocean floor. Ralph White/CORBIS had carried these rocks there. As the melting icebergs floated When molten lava oozes from cracks in the ocean floor, it mixes with the icy water to form shapes known as pillow lava. 14 010_018_CR14_LR_G6_U1W4L60_O_118642.indd 14 10/02/12 3:56 PM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF In the 2002 expedition to Alaska, scientists were exploring and mapping underwater mountains known as seamounts. They explored a chain of seamounts that extended from the Gulf of Alaska toward the western coast of the United States and Canada. The largest seamount was more than 9,900 feet tall. To map the seamounts, scientists on Atlantis used a sonar system and an echo sounder. The sonar system measured the depth of the seafloor over a wide area. The echo sounder enabled the scientists to measure the height of the seamounts. Together, they allowed scientists to create a 3-D map of the seafloor. Using this map, scientists could select the areas they wished to explore Dr Peter Etnoyer/Marine Conservation Biology Institute & National Oceanic and Atmospheric Administration (NOAA) more closely while aboard Alvin. Marchand Seamount Chirikof Seamount Murray Seamount Patton Seamount This computer image shows the seamount chain that was mapped in 2002. KEY High Low 15 010_018_CR14_LR_G6_U1W4L60_O_118642.indd 15 10/02/12 3:56 PM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF UPGR ADING ALVIN Alvin has had a busy life, averaging more than 180 dives each year. It can travel to a depth of 15,000 feet, which means it can reach and explore more than half of the ocean floor. To get to even more of the ocean floor, scientists at upgrade Alvin. The new Alvin will be able to dive to 20,000 feet. It will be able to reach 99 percent of the ocean floor and remain submerged for up to 12 hours. Over the next two decades, scientists hope to use the new HOV to continue exploring the deep ocean. They plan to build on the knowledge of tectonic forces and deep-sea life that has been gathered using Alvin. Dorling Kindersley/Dorling Kindersley/Getty Images Woods Hole Oceanographic Institution are planning to This drawing shows what the new Alvin might look like. 16 010_018_CR14_LR_G6_U1W4L60_O_118642.indd 16 10/02/12 3:56 PM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF CONCLUSION The exploration of the deep ocean has resulted in a wealth of knowledge about how living things exist and adapt in one of Earth’s most extreme environments. It has allowed scientists to gather firsthand information about the tectonic forces that are constantly shaping Earth. Woods Hole Oceanographic Institution Alvin, shown here exploring the Mid-Atlantic Ridge, continues to unlock the secrets of the deep. The equipment on Alvin and its support ship has helped scientists to explore underwater mountain ranges. Scientists have been able to document the way that Earth’s new crust forms at mid-ocean ridges. They have also mapped much of the ocean floor. Alvin has enabled scientists to explore more of the ocean floor than any other submarine. It has helped us understand many of the natural forces that affect Earth. 17 010_018_CR14_LR_G6_U1W4L60_O_118642.indd 17 10/02/12 3:57 PM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF Summarize Main Idea Use main ideas and key details from Detail Exploring the Deep to summarize how underwater volcanic activity affects Earth. Your graphic organizer may Detail Detail help you. Text Evidence 1. What kind of informational text is Exploring the Deep? Identify two features that tell you this. GENRE 2. On page 6, why did scientists change their ideas about life in the deep ocean? Identify the key details that support the main idea. MAIN IDEA AND KEY DETAILS 3. To what does the author compare a thermal vent on page 7? How does the simile help you understand how scientists thought thermal vents would work? METAPHOR AND SIMILE 4. In Chapter 2, what is the main purpose of the Alvin explorations? Write about the details that illustrate this. WRITE ABOUT READING 18 010_018_CR14_LR_G6_U1W4L60_O_118642.indd 18 10/02/12 3:57 PM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF Compare Texts Read about a scientist who studies the natural forces that affect Earth. Curious About Earth Hamish Campbell is a geologist who studies the oceans. He decided to study geology GNS Science Photo Library in college because he was curious about Earth. The first lecture he attended, on undersea geology, mesmerized him. In that first lecture, the students saw photographs of underwater volcanoes. The images showed lava erupting from the seafloor. The students were seeing pillow lava—it looked as if the underwater volcanoes were making a string of giant underwater sausages. Campbell has been hooked on geology ever since. Hamish Campbell has studied the black smoker found on Alvin’s 1999 mission. 19 019_024_CR14_LR_G6_U1W4L60_O_118642.indd 19 27/01/12 2:04 PM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF Later, Campbell specialized in paleontology. Paleontologists study ancient fossils. These are the remains of plants and animals that scientists believe to be millions of years old! One fascinating area of Campbell’s work focuses on radiolarians. These are tiny marine animals. Radiolarians survive by eating even tinier animals from the ocean. Campbell studies their fossilized skeletons to find out what the oceans used to be like. Paleontologists such as Campbell can figure out the age of fossils by identifying the layer of rock they are found in. significantly between 230 and 260 million years ago. What caused these changes? Most scientists agree that a catastrophe occurred on Earth about 250 million years ago. They know this from studying rocks. Some scientists think a giant meteor may have caused it. Comstock Images/Comstock Images/Getty Images Paleontologists have discovered that radiolarians changed Radiolarians are so small you need a microscope to see them. 20 019_024_CR14_LR_G6_U1W4L60_O_118642.indd 20 27/01/12 2:04 PM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF GNS Science Photo Library Here, Hamish Campbell shares his interest in deep-ocean geology with radio listeners. That catastrophe was the biggest mass extinction of all time. Scientists think 90 percent of all living things on our planet may have died. They want to know what forces caused the mass extinction, and they’d also like to discover how a few species managed to survive. Scientists including Hamish Campbell are still searching for the exact rock layer that will give them clues to what happened. This is what makes geology so interesting for Campbell. There’s still so much waiting to be discovered, and if scientists can figure out what happened in the past, it will help us understand more about forces that continue to affect Earth. Make Connections Why does Hamish Campbell study natural forces? ESSENTIAL QUESTION How do Hamish Campbell and the crew on board Alvin all study natural forces? TEXT TO TEXT 21 019_024_CR14_LR_G6_U1W4L60_O_118642.indd 21 27/01/12 2:04 PM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF Glossary basalt (buh-SAWLT) a kind of rock formed from volcanic eruptions (page 10) catastrophe (kuh-TAS-truh-fee) disaster (page 20) embedded (im-BE-duhd) fixed firmly into something (page 14) habitat (HA-bah-tat) a place where a plant or animal normally lives and grows (page 11) mantle (MAN-tuhl) the part of Earth between the crust and the core (page 13) molten (MOHL-tuhn) melted by heat (page 4) overhauls (oh-vuhr-HAWLS) repairs (page 12) paleontology (pay-lee-ahn-TAH-luh-jee) the study of fossils (page 20) rift (rift) a long crack or break in the land (page 4) sonar (SOH-nahr) a system of detecting objects underwater (page 15) superheated (sew-puhr-HEE-tuhd) hotter than boiling (page 9) tectonic (tek-TAH-nik) to do with the crust of Earth (page 4) viewports (VYEW-ports) small windows in a ship or submarine (page 8) 22 019_024_CR14_LR_G6_U1W4L60_O_118642.indd 22 27/01/12 2:04 PM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF Index black smokers, 8, 9, 11, 19 Campbell, Hamish, 19–21 Corliss, Jack, 6 East Pacific Rise, 8, 10 Galapagos Rift, 4, 6, 14 mid-ocean ridges, 7, 8, 10, 11 Pangaea, 5 seafloor spreading, 4, 6, 10 Shumaker, Larry, 6–8 tectonic plates, 4–6, 14, 16 thermal vents, 6–9, 11, 13, 14 Wegener, Alfred, 5 Woods Hole Oceanographic Institution, 3, 16 23 019_024_CR14_LR_G6_U1W4L60_O_118642.indd 23 27/01/12 2:04 PM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF Purpose To explain how a natural force affects Earth Procedure Step 1 Choose an example of a natural force on Earth. Step 2 Carry out research in the library or online to gather information about the force you’ve chosen. Step 3 Design a poster or presentation that explains to an audience this force and its effect on Earth. You’ll need to consider the ages and the background knowledge of your audience. Step 4 Display the poster or give the presentation. Ask your audience for feedback to ensure that they understood how the force affects Earth. Conclusion How did sharing information about the way a natural force affects Earth help you to understand it better? 24 019_024_CR14_LR_G6_U1W4L60_O_118642.indd 24 27/01/12 2:04 PM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF Literature Circles Nonfiction The Topic What is Exploring the Deep mostly about? Text Structure In what order does the author give us the information in the text? Vocabulary What are the key words in this text that relate to the topic? Conclusions What did you conclude about the forces of nature? What are the most important things you learned? Make Connections What other books about exploration have you read? What challenges did the explorers face? IFCIBC_CR14_LR_G6_U1W4L60_O_118642.indd 3 27/01/12 1:53 PM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF Dynamic Earth Science GR V • Benchmark 60 • Lexile TK Grade 6 • Unit 1 Week 4 www.mheonline.com ISBN-13 978-0-02-118642-6 MHID 0-02-118642-1 99701 EAN 9 780021 186426 CV_CR14_LR_G6_U1W4L60_O_118642.indd 2 6 27/01/12 1:52 PM Program: CR 14 Component: LR Vendor: Learning Media Level: 60 G6 U1 W4 O PDF