Unit4AmazingScienceTopic1Whenwasitinvented
SectionD•What’situsedfor
•It’susedforlisteningtomusic
•What’sitmadeof
•It’smadeofplastic
•Wherewasitinvented
•ItwasinventedinKorea
•Whenwasitinvented
•Itwasinventedin1998
listentomusic/plastic/Korea/1998•What’situsedfor
•It’susedforcommunicatingeasily
•What’sitmadeof
•It’smadeofplasticandmetal
•Wherewasitinvented
•ItwasinventedinAmerica
•Whenwasitinvented
•Itwasinventedin1973
communicateeasily/plasticandmetal/America/1973What’sthis
What’situsedfor
Howdidtheearlyexplorersknowwheretheywere
Theyfoundoutwheretheywerebyusingstars
What’sthedisadvantageofusingthestarsasguidingmarks
Itsdisadvantageisthatitdidn’tworkwellwhentheweatherwasbadandthestarscouldnotbeseen
ReadthepassageanddiscussthequestionsonPage88
WhatisaGPS
Isitusefultous
Itislikeaman-ma