Unit1 Mister Imagination

Unit2 High Up in the Tropics

Unit3 Education Out of School

Unit4 Taming the Elphant

Unit5 A French Boy's Adventure in Canada

Unit6 Telling the Time

Unit7 More People and More Products

Unit8 Useful Companions

Unit9 A Time of Revolutions

Unit10 Engineers of the Woods

Unit11 The Telephone and Its Inventor

Unit12 Brave Ballerina

Unit13 The Day the Big Top Burned

Unit14 The Secluded Life

Unit15 The lITTLE pEOPLE

Unit16 Mississippi Steamboat Days

Unit17 Tough Teen to Tennis Queen

Unit18 Freedom from Pain

Unit19 Never Trust Appearance

Unit20 Glass

Unit21 Informing the World

Unit22 Life among the Aztecs

Unit23 Traveling Students

Unit24 How Nice to Be Clean

Unit25 Cats Are No Good But

Unit26 Bringing Up Children

Unit27 Ghosts for Tea

Unit28 New York's Big Ditch

Unit29 Picnic in the Dining-room

Unit30 Etipuette

Answer Key(另附)