-（理屈词穷，无话可说）beagapeandtongue-tied;beatalossforwords;bestumpedby...;beunabletofindanythingtosay;gapingandspeechless;loseone'stongue;One'stongueglueditselftotheroofofone'smouth.;One'stonguerefusedtomove.;openthemouthandholdthetongue--cannotanswer;tongue-tied:
Hewasstumpedbythequestionsandremainedtongue-tiedforagoodwhile.他被问得张口结舌，半天说不出话来。
Broughtbeforetheevidenceofhiscrimes,hewasawe-struckandcouldsaynothinginhisdefence.罪证俱在，他张口结舌，无言以对。
-（惊异得说不出话来）gapewithastonishment[wonder];gapingatwithwonder