Inordertoprotectvaluableenergy,snails(蜗牛)basicallyplayagameoffollow-the-leader,anewstudyfinds.Snailscreatetrailsofmucus(黏液)tohelpthemmovesmoothlyacrosstheground,mainlyinsearchoffoodorapartner,butmakingallthatmucususesupalotofenergy.

“Snailsusealotofenergy,probablyathird,creatingmucus,”saidMarkDaviesoftheUniversityofSunderland,leadauthorofthestudypublishedinthejournalProceedingsoftheRoyalSociety.“Thisprocessisverytiringindeed—muchmoresothanwalking,swimmingorflying.”

DaviesandhisworkmatesstudiedmarinesnailsoffthecoastofBritainanddiscoveredthattosavesomeofthisimportantenergy,thesnailssometimesfollowtheexistingmucustrailslaiddownbyothersnailstogetaroundandsoonlyhavetocreateasmallpartofthemucusneededtomakeanewtrail.

“Thefactthattheycanmakesavingshasaneffectonasmuchastheyhavetosavemoreenergytodootherthingslikereproducing,”Daviessaid.

Theenergysavingmayalsohelpsnailswhichliveinenvironmentswherefoodisnotenough,makingtheenergyhardertoreplace.

Biologistshadlongguessedthatsnailsbehavedthisway,butthisisthefirststudytodirectlyobserveit.Daviessaidthatitislikelythatallsnailsusethismeansofcuttingenergyastheyworkhardthroughlife.

45.What’sthefunctionofmucusthatsnailscreate?

A.Tofindtheirfood B.Tofindtheirwayback

C.Tosavetheirenergy D.Tohelpthemmovesmoothly

46.Accordingtothepassage,whichofthefollowingstatementsisTRUE?

A.Thesnail’slifeisveryhard.

B.Thesnailsdon’tneedmuchtoreproduce.

C.Thisisthefirsttimetodotheguess.

D.Thesnailswillreplacemoreenergyinplaceslackingfood.

47.Fromthepassageweknowthat______.

A.snails’trailsaresometimesreused

B.snails’foodisdifficulttofind

C.snailscanliv