【Coralreefs(珊瑚礁)arenotjustbeautifultolookat,butalsoveryuseful.Theyshelternearly25%ofoceanlifeandprovidefoodforbillionsofpeople.Howeverlikemanyotherspecies,thisamazingecosystem(生态系统)isin】
Coralreefs(珊瑚礁)arenotjustbeautifultolookat,butalsoveryuseful.Theyshelternearly25%ofoceanlifeandprovidefoodforbillionsofpeople.Howeverlikemanyotherspecies,thisamazingecosystem(生态系统)isindangerofdyingout!
Therearetwomainreasonsforthedestruction—therisingcarbondioxidelevelscausedbyglobalwarmingaswellashumaninfluenceslikebottomoperation.Whilenotmuchcanbedoneabouttheformer,thelosscausedbythelattercanbereduced.
Bottomoperationinvolvesdroppingnetstotheoceanbedandthendraggingthemupwhenfilledwithfish.Thisactiondamagedtheoceanfloor,causingthecoralbranchestoseparatefromthereefs.Whilethatisverydiscouraging,thegoodnewsisthatifthesebranchesarefoundquickly,theycanbesaved.Atpresent,thatworkisbeingperformedbyvolunteerdivers.Butthemethodhasonlylimitedsuccessbecausetheycannotstaylongunderwaternorreachdepthsofover200meterswheresomeofthedeep-seacoralgrows.
However,thisisnotthecaseforCoralbots—therobotsthatcanconstantlyseekoutbrokenbranches.Ateamof‘coralbots’,eachindividuallyworkingtosimpleruleswillpiecetogether’damagedbitsofcoralallowingthemtoregrow.Theyareprogrammedtobeabletodistinguishbetweenotherthingsandthecoral.Therobotsworktogetheringroups,similartobees.Ifonecoralbotisdamagedthentheotherswillstillbeabletocompletethetask.
DrLea-AnneHenrysaid:“Theprojectofusingcoralbotsoffersusthepossibilitytorestore(修复)thefunctionofreefs.Itisinthefinalstageoftesting.OncereadytheresearchershopetobuildhundredsofthemandusethemeffectivelyinthewatersoffScotlandandthenhopefullyintheoceansacrosstheworld.”
1.Whichofthefollowingisacauseofthedangerthatcoralreefsarefacing?
A.Theappearanceofnewcreatures.
B.Theseriouslypollutedseawater.
C.Theactivitiesofvolunteerdivers.
D.Humanactivitieslikebottomoperation.
2.Comparedwithvolunteerdivers,coralbots______________.
A.canstaylongerunderwater
B.mustworkasbeesdo
C.candistinguishwhatiscoral
D.canneverbedamaged
3.Whatdoestheunderline