U字開頭的單詞或詞組
UNCuncorkunabatedundergradutiunstuckunhelpfulurinateunderworldupper-classuntouchedundisputedunisonupmostunusableunaidedunbindunrecordeduninterestedunrequitedunsophisticatedunsatisfactoryunemployment rateunchangeableunpreparedunsettlinguninhabitedunderlayunfruitfulUSAFunspeakableunoriginalulcerativeunfetteredunproductiveundeterminedupper lipunchangedupperclassmanunder the control ofunchartedupheaval