我不愿做他们吵架的见证人.I was an unwilling witness of their quarrel.见证人证实了警察的陈述.Witnesses corroborated the policeman's statement.让这些人站成一排看看见证人能否从中把罪犯认出来.Line up these men and see if the witness can recognize the criminal....

“见证人”的英语可以翻译为：eyewitness，witness，[法] attesting witness，eye-witness，[电影]Amen....