The Canadian researchers randomly assigned about half of the addicts to receive methadone and the other half to receive daily injections of diacetylmorphine, the active ingredient in heroin.
加拿大的研究者【将】受验者随机分组,一半接受美沙酮的治疗,另一半每天接受注射二乙酰吗啡,主要成分是洛因【为洛因的主要成分】。