U字開頭的單詞或詞組
unzipuselessunfoldingundergoneusher inuntidyupunlikeunwillingunder the circumstancesunderestimateUUTunderneathunemployeduglifyunderwentutilizationunicornuniquenessuse upuncommonur-underlineunsupportedunavailableUTunhealthyurge sb to do sthupdatingurbanizationunrecognizedunpredictableunleashunbearableunderwearusageundouppercaseunawareunder the tableunfamiliarunusually