根据下列内容，回答216-220题。 Lookingbackonmychildhood，Iamconvincedthatnaturalistsarebornandnotmade． AlthoughWewerebroughtupinthesameway，mybrothersandsisterssoonabandonedtheirpressedflowersandinsects．Unlikethem，Ihadnoearformusicandlanguages．1wasnotanearlyreaderandIcouldnotdomentalarithmetic. BeforeWorldWarIwespentoursummerholidaysinHungary.Ihaveonlythedimmemoryofthehousewelivedin,ofmyroomandmytoys.NordoIrecallclearlythelargefamilyofgrandparents,aunts,unclesandcousinswhogatherednextdoor.ButIdohaveacrystal-clearmemoryofdogs,thefarmanimals,thelocalbirdsandaboveall,theinsects. Iamanaturalist,notascientist.Ihaveastrongloveofthenaturalworld,andmyenthusiasmhasledmeintovariedinvestigations.Ilovediscussingmyfavoritetopicsandenjoyburningthemidnightoil,readingaboutotherpeople'sobservationsanddiscoveries.Thensomethinghappensthatbringstheseobservationstogetherinmyconsciousmind.Suddenlyyoufancyyouseetheanswertothefiddle,becauseitallseemstofittogether.Thishasresultedinmypublishing300papersandbooks,whichsomemighthonorwiththetitleofscientificresearch. Butcuriosity,akeeneye,agoodmemoryandenjoymentoftheanimalandplantworlddonotmakeascientist;oneoftheoutstandingandessentialqualitiesrequiredisself-discipline,aqualityIlack.Ascientistcanbemade.Anaturalistisborn.Ifyoucancombinethetwo,yougetthebestofbothworlds. Accordingtotheauthor,abornnaturalistshouldfirstofallbe__________.
A.full of ambition B.self-disciplined C.full of enthusiasm D.knowledgeable正确答案C
