1、by Maria GillChanging LandscapesExpository TextPAIREDREADStudents Save WetlandsProgram:CR 14Component:LRG4 U1 W3 APDFVendor:Learning MediaLevel:30CV_CR14_LR_G4_U1W3L30_A_119133.indd 2CV_CR14_LR_G4_U1W3L30_A_119133.indd 28/02/12 9:33 AM8/02/12 9:33 AMSTRATEGIES&SKILLSAPhotography Credit:CORBIS/SuperS
2、tock *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.ComprehensionStrategy:RereadSkill:Compare and ContrastVocabulary StrategyMultiple-Meaning WordsVocabularyalter,collapses,crisis,destr
3、uction,hazards,severe,substantial,unpredictableContent StandardsScience Earth ScienceWord Count:762*Program:CR 14Component:LRG4 U1 W3 APDFVendor:Learning MediaLevel:30Copyright The McGraw-Hill Companies,Inc.All rights reserved.No part of this publication may be reproduced or distributed in any form
4、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 EducationTwo Penn PlazaNew York,New York 1
5、0121ISBN:978-0-02-119078-2MHID:0-02-119078-XPrinted in the United States.1 2 3 4 5 6 7 8 9 QLM 15 14 13 12 11 10IFCIBC_CR14_LR_G4_U1W3L30_A_119133.indd 2IFCIBC_CR14_LR_G4_U1W3L30_A_119133.indd 28/02/12 9:37 AM8/02/12 9:37 AMby Maria GillChanging LandscapesEssential Question How do people respond to
6、natural disasters?PAIREDREADIntroduction .2Chapter 1Crumbling Landscapes.4Chapter 2Sudden Changes!.8Chapter 3Fixing the Damage.12Conclusion.14Respond to Reading.15Students Save Wetlands .16Glossary/Index.19 Focus on Science.20Program:CR 14Component:LRG4 U1 W3 APDFVendor:Learning MediaLevel:30001_009
7、_CR14_LR_G4_U1W3L30_A_119133.indd 1001_009_CR14_LR_G4_U1W3L30_A_119133.indd 113/02/12 9:20 AM13/02/12 9:20 AMImagine you travel back in time thousands of years.You arrive in a wild landscape that youve never seen before.Its actually where you live now.Youd never guess it!Why does it look so differen
8、t?IntroductionWater carved out this canyon.2Program:CR 14Component:LRG4 U1 W3 APDFVendor:Learning MediaLevel:30CORBIS/SuperStock001_009_CR14_LR_G4_U1W3L30_A_119133.indd 2001_009_CR14_LR_G4_U1W3L30_A_119133.indd 213/02/12 9:20 AM13/02/12 9:20 AMThe biggest changes to Earth take thousands of years.Mou
9、ntains and cliffs slowly wear away.Rivers become wider.Some changes to the landscape can happen very quickly.Natural disasters,such as hurricanes and floods,can alter the landscape suddenly.Some places have natural features that help protect the land from natural disasters.The huge waves from a hurr
10、icane can change the coastline.3Program:CR 14Component:LRG4 U1 W3 APDFVendor:Learning MediaLevel:30Shaun Lowe/Vetta/Getty Images001_009_CR14_LR_G4_U1W3L30_A_119133.indd 3001_009_CR14_LR_G4_U1W3L30_A_119133.indd 313/02/12 9:20 AM13/02/12 9:20 AMWater can make big changes to the surface of the earth.R
11、ivers and streams shape the landscape.Small streams and rivers begin in the mountains.The water flows downhill.The moving water carries sediment,or small rocks and sand with it.The movement of the rock and sand is called erosion.Crumbling LandscapesChapter 1HOW rivers Change 1.A fast moving river cu
12、ts a path through the land.2.Over time,the river wears away more of the land.3.The river leaves behind rocks and sand and forms a plain.1234Program:CR 14Component:LRG4 U1 W3 APDFVendor:Learning MediaLevel:30Illustration:Sarah Anderson 001_009_CR14_LR_G4_U1W3L30_A_119133.indd 4001_009_CR14_LR_G4_U1W3
13、L30_A_119133.indd 413/02/12 9:20 AM13/02/12 9:20 AMThe water from waves changes the shape of a coast.Waves can make cracks in cliffs.Waves also wear away the bottom of cliffs.They slowly break rocks into smaller pieces and sand.The breaking down of large rocks into smaller pieces is called weatherin
14、g.The wind also causes erosion.Wind blows the sand,and hills of sand called dunes form.Erosion has worn away these cliffs.5Program:CR 14Component:LRG4 U1 W3 APDFVendor:Learning MediaLevel:30 Stephen Reynolds001_009_CR14_LR_G4_U1W3L30_A_119133.indd 5001_009_CR14_LR_G4_U1W3L30_A_119133.indd 513/02/12
15、9:20 AM13/02/12 9:20 AMSome places have natural features that protect them against erosion.On beaches,sand dunes get bigger as wind and waves add more sand.Larger dunes act as barriers.They trap the sand that is brought on land by the waves and wind.Grasses growing on the dunes also keep the sand fr
16、om blowing away.Wetlands slow down erosion,too.Wetlands are marshes or swamps.They are found near rivers and lakes.They are also found near the coast.Wetlands act like sponges.They soak up water when it rains.This prevents flooding.Swamp PlantsThe Venus flytrap grows in swamps or wetlands.It feeds o
17、n insects.The insects give the plant nutrients.6Program:CR 14Component:LRG4 U1 W3 APDFVendor:Learning MediaLevel:30Steven P.Lynch001_009_CR14_LR_G4_U1W3L30_A_119133.indd 6001_009_CR14_LR_G4_U1W3L30_A_119133.indd 613/02/12 9:20 AM13/02/12 9:20 AMPlants that love the water grow in wetlands.Their roots
18、 hold the soil in place.This helps prevent erosion.How do water and wind changealandscape?STOP AND CHECKHOW A WETLAND WORKSWater is absorbed and stored.Wetland1.A stream slows down.2.Sediment settles and nutrients are absorbed.3.Cleaner water leaves the wetland.7Program:CR 14Component:LRG4 U1 W3 APD
19、FVendor:Learning MediaLevel:30Illustration:Sarah Anderson 001_009_CR14_LR_G4_U1W3L30_A_119133.indd 7001_009_CR14_LR_G4_U1W3L30_A_119133.indd 713/02/12 9:20 AM13/02/12 9:20 AMSudden Changes!Chapter 2A landslide hit this town in California.8Program:CR 14Component:LRG4 U1 W3 APDFVendor:Learning MediaLe
20、vel:30Mark Reid/USGS001_009_CR14_LR_G4_U1W3L30_A_119133.indd 8001_009_CR14_LR_G4_U1W3L30_A_119133.indd 813/02/12 9:20 AM13/02/12 9:20 AM Natural disasters change the land more quickly than erosion.Heavy rain can cause landslides.The ground becomes soaked.It cant absorb any more water.Rocks and soil
21、slide downhill.Sometimes the hillside collapses.Earthquakes and volcanic eruptions can also cause landslides.These events are unpredictable and often happen without warning.Landslides can move very quickly.They can sweep away roads,bridges,and buildings.Landslides are less likely to happen on hills
22、with lots of trees and plants.This is because the roots of trees and plants help to keep the soil in place.Their roots also absorb water in the soil.9Program:CR 14Component:LRG4 U1 W3 APDFVendor:Learning MediaLevel:30001_009_CR14_LR_G4_U1W3L30_A_119133.indd 9001_009_CR14_LR_G4_U1W3L30_A_119133.indd
23、913/02/12 9:20 AM13/02/12 9:20 AMSevere winds and rain from hurricanes also cause destruction and change the land.Hurricanes are substantial storms that begin in the ocean.When a hurricane nears land,the wind makes huge waves.The waves wash away sand from beaches.A beach can be much smaller after a
24、hurricane.Strong winds and rain from Hurricane Katrina caused a lot of damage.10Program:CR 14Component:LRG4 U1 W3 A2RVendor:Learning MediaLevel:30010_015_CR14_LR_G4_U1W3L30_A_119133.indd 10010_015_CR14_LR_G4_U1W3L30_A_119133.indd 108/02/12 9:27 AM8/02/12 9:27 AMCoastal wetlands protect areas from hu
25、rricanes.A hurricane can cause a huge wall of water to hit the coast.Wetlands can absorb some of that water.AVIn 2005,Hurricane Katrina was a crisis for people living along the Gulf Coast.The hurricane caused a huge wall of water to tear through barriers and riverbanks.Many areas were flooded.Hurric
26、ane KatrinaSTOP AND CHECKWhat damage do hurricanes andlandslides cause?11Program:CR 14Component:LRG4 U1 W3 A2RVendor:Learning MediaLevel:30NOAA/Department of Commerce010_015_CR14_LR_G4_U1W3L30_A_119133.indd 11010_015_CR14_LR_G4_U1W3L30_A_119133.indd 118/02/12 9:27 AM8/02/12 9:27 AMPeople often help
27、cause erosion when they cut down trees or plants to build roads or houses.Wetlands,sand dunes,and trees protect against erosion.Without them,rain washes away soil and causes more damage,such as landslides.Planting trees and plants with long roots helps prevent hazards such as landslides.The roots ab
28、sorb water.They hold the soil in place.Fixing the DamageChapter 3Trees and plants with deep roots help prevent landslides.12Program:CR 14Component:LRG4 U1 W3 A2RVendor:Learning MediaLevel:30(l)watershed regeneration by AMURT Haiti.Subuddhyananda,(r)An example of the results of watershed regeneration
29、 Subuddhyananda010_015_CR14_LR_G4_U1W3L30_A_119133.indd 12010_015_CR14_LR_G4_U1W3L30_A_119133.indd 128/02/12 9:27 AM8/02/12 9:27 AMPeople can restore wetlands and dunes to keep erosion from happening.In the past,people have built homes and buildings on wetland areas.Now we realize that wetlands help
30、 prevent erosion.People can make plans to prevent erosion.They can replant wetlands or move sand back into the dunes.Restoring wetlands helps prevent erosion.STOP AND CHECKHow can people keep erosion from happening?13Program:CR 14Component:LRG4 U1 W3 A2RVendor:Learning MediaLevel:30Gulf Oil Spill/Aa
31、ron Roeth Photography010_015_CR14_LR_G4_U1W3L30_A_119133.indd 13010_015_CR14_LR_G4_U1W3L30_A_119133.indd 138/02/12 9:27 AM8/02/12 9:27 AMImagine youve moved back in time again.Youve seen the slow changes to mountains,rivers,and coasts caused by erosion.Natural disasters can change the land suddenly.
32、We cant stop disasters from happening,but we can work to prevent some of the damage caused by them.ConclusionStudents plant grasses at a wetland in Maryland.14Program:CR 14Component:LRG4 U1 W3 A2RVendor:Learning MediaLevel:30ZUMA Press/Newscom010_015_CR14_LR_G4_U1W3L30_A_119133.indd 14010_015_CR14_L
33、R_G4_U1W3L30_A_119133.indd 148/02/12 9:27 AM8/02/12 9:27 AMSummarizeSummarize what you have learned from Changing Landscapes.Useyour graphic organizer tohelp.Text Evidence1.How can you tell Changing Landscapes is anexpository text?GENRE2.Compare the three diagrams of a river on page 4.What is the sa
34、me?What is different?COMPARE AND CONTRAST3.What is the meaning of wear on page 3?What words help you figure out the meaning?MULTIPLE MEANING WORDS4.Write about the similarities and differences between landslides and hurricanes.Use details from the text in your answer.WRITE ABOUT READING15Program:CR
35、14Component:LRG4 U1 W3 A2RVendor:Learning MediaLevel:30010_015_CR14_LR_G4_U1W3L30_A_119133.indd 15010_015_CR14_LR_G4_U1W3L30_A_119133.indd 158/02/12 9:27 AM8/02/12 9:27 AMCompare TextsRead about how students in Florida are helping toprevent erosion.People are working to restore the wetlands in Tampa
36、 Bay,Florida.As the city grew,the wetland areas were damaged or destroyed.Today people know that wetlands act as barriers against storms.They help prevent erosion.They provide homes for birds and fish.Students in Tampa Bay are planting grasses in the wetlands.The grasses hold the soil in place.Stude
37、nts Save Wetlands16Program:CR 14Component:LRG4 U1 W3 APDFVendor:Learning MediaLevel:30016_020_CR14_LR_G4_U1W3L30_A_119133.indd 16016_020_CR14_LR_G4_U1W3L30_A_119133.indd 1613/02/12 9:21 AM13/02/12 9:21 AM1.The students plant grasses in a pond.2.They check the growth of the grasses.They test the wate
38、r.3.After six to eight months,the students dig up the grasses.They separate the grasses out and replant them.Now the grasses have more room to grow.4.When the grasses have grown,the students plant them in a wetland!How to Grow Wetland Grasses17Program:CR 14Component:LRG4 U1 W3 APDFVendor:Learning Me
39、diaLevel:30Yvette C.Hammett/Staff016_020_CR14_LR_G4_U1W3L30_A_119133.indd 17016_020_CR14_LR_G4_U1W3L30_A_119133.indd 1713/02/12 9:21 AM13/02/12 9:21 AMMake ConnectionsWhy is it important to restore wetlands?ESSENTIALQUESTIONHow do people in Changing Landscapes and Students Save Wetlands prevent eros
40、ion?TEXT TO TEXTThe grasses the students have planted will help prevent erosion.The grasses will also be habitats for the animals and fish living there.The students have made a big difference.They have restored almost 24 acres of wetlands on the Florida coast.Healthy Coastal AreasStudents plant sea
41、grasses.18Program:CR 14Component:LRG4 U1 W3 APDFVendor:Learning MediaLevel:30Farmer and Rancher Newspaper016_020_CR14_LR_G4_U1W3L30_A_119133.indd 18016_020_CR14_LR_G4_U1W3L30_A_119133.indd 1813/02/12 9:21 AM13/02/12 9:21 AMGlossaryIndexflooding,3,6,11Hurricane Katrina,10,11hurricanes,3,10,11landslid
42、es,8,9,12sand dunes,5,6,12,13wetlands,6,7,1113,1618barriers (BAR-ee-urz)obstacles that stop things from getting through (page 6)erosion (i-ROH-zhuhn)wearing away caused by rain,wind,or glacial ice (page 4)restore (ri-STAWR)return something to how it was (page 13)sediment (SED-uh-muhnt)rocks and sand
43、 carried and dropped by water or wind (page 4)weathering (WETH-uhr-ing)the slow wearing away of rocks (page 5)wetlands (WET-landz)areas of land that are covered by water some part of the time (page 6)19Program:CR 14Component:LRG4 U1 W3 APDFVendor:Learning MediaLevel:30016_020_CR14_LR_G4_U1W3L30_A_11
44、9133.indd 19016_020_CR14_LR_G4_U1W3L30_A_119133.indd 1913/02/12 9:21 AM13/02/12 9:21 AMStep 1Step 2Step 3Step 4Purpose To understand the kinds of damage a natural disaster can cause and how to prepare in advanceProcedurePick a type of natural disaster you want to learn more about.You might choose a
45、natural disaster that is common where you live.Use the library or the Internet to research the kinds of damage the natural disaster causes.Research the ways that people can prepare in advance for the natural disaster,such as making an emergency kit.Create a poster that summarizes what you learned.Ma
46、ke sure you include what the disaster is,the hazards it creates,and how people can prepare and stay safe.Conclusion Being prepared helps us to stay safe.What have you learned about planning for a natural disaster?20Program:CR 14Component:LRG4 U1 W3 APDFVendor:Learning MediaLevel:30016_020_CR14_LR_G4
47、_U1W3L30_A_119133.indd 20016_020_CR14_LR_G4_U1W3L30_A_119133.indd 2013/02/12 9:21 AM13/02/12 9:21 AMLiterature CirclesNonfictionThe TopicWhat is Changing Landscapes mostly about?Text StructureHow does the author organize information inChanging Landscapes?VocabularyWhat new words did you learn in the
48、 text?What helped you understand their meanings?ConclusionsWhat is the most important thing you learned about preventing erosion?Authors PurposeWhy do you think the author wrote Changing Landscapes?What message did the author want you to get from the book?Program:CR 14Component:LRG4 U1 W3 APDFVendor
49、:Learning MediaLevel:30IFCIBC_CR14_LR_G4_U1W3L30_A_119133.indd 3IFCIBC_CR14_LR_G4_U1W3L30_A_119133.indd 38/02/12 9:37 AM8/02/12 9:37 AMGrade 4 Unit 1 Week 3GR N Benchmark 30 Lexile TKTake ActionScience9780021 190782MHID 0-02-119078-XISBN-13 978-0-02-119078-299701EAN4Program:CR 14Component:LRG4 U1 W3 APDFVendor:Learning MediaLevel:30CV_CR14_LR_G4_U1W3L30_A_119133.indd 1CV_CR14_LR_G4_U1W3L30_A_119133.indd 18/02/12 9:33 AM8/02/12 9:33 AM
