1.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.

1.加拿大的研究者对【】者随机分组，一半沙酮的治疗，另一半每注射二乙酰吗啡，主要成分是海洛因【为海洛因的主要成分】。