The answer is methadone. It is also a form of opioid and used to treat people experiencing extreme pain. it is also used to treat addiction to other opioids. It can give a similar feeling and inhibit withdrawal symptoms. It is generally less potentially harmful than heroin because it blocks the high you get from addictive drugs like codeine, heroin, morphine and etc.
I believe the answer is :Random sampling
Random sampling refers to select a group of subjects that could be used as sample for a research from a large population. The selection is beind done without any criteria in hope that the sample at least represent the general composition of the population.
