Lifeisacontest!Whowillwin?Abluebirdandsparrowbothcompeteforspacetobuildtheirnests.Afast-growingmapletreeandslower-growingdogwoodcompeteforthesunlighttheybothneed.Oilcompeteswithcoalandnuclearpowerasanenergysourceforelectricpowerplants!
Thereisaproblem.Thereisalimitedamountofspaceforbirds,sunlightfortrees,andenergyforpeople!Ifwedonotcutbackonourusesofsomeofourresources,somedaytheywillbegone!
Howcanweuseenergytodayandknowwewillhaveenoughtogoaroundinthefuture?Wecanchoosealternate,orreplacement,energyresources.Ittakestheearthmillionsofyearstocreatecoal,oil,andgas.Theyarenonrenewableresources.
Solarenergy,windenergyandwaterenergyarerenewableresources.Ittakestheearthmillionsofyearstocreatecoal,oil,andgas.Theyarenonrenewableresources.
Solarenergy,windenergyandwaterenergyarerenewable.Whatotherwayscanweconserveoursources?Howcanwemakesurethereisalwaysenoughtogoaround?
Usefulwordsandexpressions:
6.nonrenewableresources不可再生资源