World Book's Learning LaddersHelpersWORLDBOOKwww.worldbook.comWorld Book,Inc.180 North LaSalle StreetSuite 900USAFor information about other World Book publications,visit our website at www.worldbook.com or call1-800-WORLDBK(967-5325).For information about sales to schools and libraries,call 1-800-975-3250(United States);1-800-837-5365(Canada).2014(revised printing),2011 World Book,Inc.All rights reserved.This book may not be reproducedin whole or in part in any form without prior written permission from the publisher.WORLD BOOK and the GLOBE DEVICE are registered trademarks or trademarks of World Book,Inc.The Library of Congress has cataloged an earlier editionStaffof this title as follows:Executive CommitteePresident:Jim O'RourkeCommunity helpers.Vice President and Editor in Chief:Paul A.Kobasap.cm.-(World Book's leaming ladders)Vice President,Finance:Donald D.KellerIncludes index.Vice President,Marketing:Jean LinSummary:"Introduction to people who work in aVice President,International Sales:Maksim Rutenbergcommunity using simple text,illustrations,and photos.Director,Human Resources:Bev EckerFeatures include puzzles and games,fun focts,aresource list,and an index"-Provided by publisher.Editorial1SBN978-0-7166-7737-6Director,Digital Print Content Development:Emily Kline1.Community life--Juvenile literature.2.Communities-Editor,Digital Print Content Development:Kendra MuntzJuvenile literature.3.Human services--JuvenileWriter:Shawn Brennanliterature.I.World Book,Inc.Manager,Indexing Services:David PofelskiHM761.C632011Manager,Contracts Compliance (Rights Permissions):307-dc22Loranne K.Shields2010022379DigitalDirector,Digital Product Development:Erika MellerDigital Product Manager:Jonathan WillsWorld Book's Leaming LaddersThis edition:Graphics and DesignISBN978-0-7166-7836-6(hc.)Senior Art Director:Tom EvansSBN978-0-7166-7845-8(set,hc.)Coordinator,Design Development and Production:Brenda B.TropinskiAlso available as:ISBN 978-0-7166-7792-5(e-book,Learning Hub)Manufacturing Manoger:Anne FritzingerISBN 978-0-7166-7793-2 (e-book,Spindle)Proofreader:Nathalie StrassheimISBN978-0-7166-77949(e-book,EPUB3)ISBN978-0-7166-7795-6(e-book.PDF月)Printed in China by Shenzhen Wing King TongPaper Products Co.,Ltd.,Shenzhen,Guangdong8th printing May 2017Shutterstock:p2,p5,p9,p26,p27,p28,p30:Shutterstock;p5,p6,p8,p18:Alamy Images;Illustrators:WORLD BOOK illustration by O2A Media