1. 名詞
   crackajack複數: 傑出的人物, 上等的物品
   

   同義字詞
   ace,adept,artist,authority,cognoscente,connoisseur,expert,fiend,geek,guru,hand,hotshot,maestro,master,maven,mavin,past master,scholar,shark,virtuoso,whiz,wizard
   beaut,beauty,corker,dandy,doozy,doozie,dream,honey,humdinger,jim-dandy,knockout,nifty,peach,pip,pippin,standout
   

例句