范文一：

　　treesareimportanttoourlife.treesprovideoxygentous.asweallknowduringphotosythesis,carbondioxideistakeninwhileoxygenisgivenoffbthetrees.sotreesareveryimportantastheyreplanishtheair.treesarealsonaturalresources,weuesedtreestomakepaperandfurniture,weeatthefruitswhichbearfromthetree.besidesallthese,treesalsohelptosaveourenvironment.therootsofthetreescanholdthesoilfirmlywhichhelpstoreducethechancesofsurfacerun-off,soilerosionandevenlandslide.lesssolparticleswillbewashedintotheriverbyrain,thustherewillbelesswaterpollutionandfloods.

　　leavesarenaturalfertilizer.whentheleavesfallontotheground.theywilldecaygradually.thedecomposedleavesaresourceofnutrientswhichcanfertilethesoil.

　　inconclusion,treesareusefulinmanyways,andtheyareveryimportanttous

　　范文二：

　　Treesareimportantandusefultohumans.Theyplayanimportantpartinourlife.

　　Theytakeharmfulgasfromtheair,andreleaseoxygen.Theyarenaturalandfreeairconditionersastheyproducecleanandfreshairforpeopletobreathe.Theypreventsoillossandreducethepossibilityofflood.Theyarealsothehomeofwildlife.Theyprovidefoodforbothhumansandanimals,.Treescanbeusedtomakealotofthings,suchasfurniture,paperandpencils.Besides,treesmaketheenvironmentmorebeautiful.

　　However,wecutdownandburnmillionsoftreeseveryyearbutreplacefewofthem.Wecanhardlyimaginehowterribleourlifewouldbeiftherewerenotrees.Treeshelphumansandtheearthinsomanyways.Theyareourfriends.