Americanblackbearsappearinavarietyofcolorsdespite(尽管)theirname.Intheeasternpart,mostofthesebearshaveshinyblackfur,butinthewesttheygrowbrown,red,orevenyellowcoats.Tothenorth,theblackbearisactuallygrayorwhiteincolor.Eveninthesamelitter(胎),bothbrownandblackfurredbearsmaybeborn.
BlackbearsarethesmallestofallAmericanbears,ranginginlengthfromfivetosixfeet,weighingfromthreehundredtofivehundredpounds.Theireyesandearsaresmallandtheireyesightandhearingarenotasgoodastheirsenseofsmell.Likeallbears,theblackbearistimidandrarelydangerous,butifattacked,mostcanclimbtreesorcovergroundatgreatspeed.Whenangryorfrightened,theyareformidable(可怕的)enemies.
Blackbearsfeedonleaves,roots,fruit,insects,fish,andevenlargeranimals.Oneofthemostinterestingcharacteristicsofbears,includingtheblackbear,istheirwintersleep.Unlikesquirrelsandmanyotherwoodlandanimals,bearsdonotactuallysleepthroughthewintermonths.Althoughthebeardoesnoteatduringthewintermonths,sustaining(维持)itselffrombodyfat,itstemperatureremainsalmostnormal,anditbreathesregularlyfourorfivetimesperminute.
Mostblackbearslivealone,exceptduringthemating(交配)season.Theyprefertoliveincaves.BabyblackbearsareborninJanuaryorFebruaryafteragestation(怀孕)periodofsixtoninemonths,andtheystaywiththeirmotheruntiltheyarefullygrownoraboutoneandahalfyearsold.Blackbearscanliveaslongasthirtyyearsinthewild,andevenlongerinsomenaturereserves.
小题1:Americanblackbearsmayhave___________coloursaccordingtothepassage.