如果关系代词在定语从句中充当介词的宾语,且介词和该关系代词一起放在定语从句句首时,则关系代词只能使用whom/which,而不能使用who/that.此题whom = the engineer,和介词with一起构成定语从句：(with whom) my fathe...- =不好意思...惭愧啊！