That quack doesn't know anything about treating heart disease.那个冒牌医生对治疗心脏病一窍不通。He was an impostor, who masqueraded as a doctor.他是个骗子，是个冒牌医生。That quack caused me more harm than the disease did.比起疾病，那个冒牌医生对我的伤害更深。He was an imposter, who masqueraded as a doctor.他是个冒牌医生。