I would say, C. Because an controlled variable is an experimental element which is constant and unchanged throughout the course of the investigation.
Sweating shaking diarrhea and cramps are symptoms of withdrawal from heroin.
Heroin is a powerful, addictive, illegal drug derived from opium. Heroin is mostly used as a recreational drug because of its feeling of great well- being and it is also used to relieve pain or in opioid replacement therapy. Heroin is commonly injected into a vein, and it can also be inhaled or smoked. The initial effect of heroin is usually fast and can last for a few hours. After the use of heroin is discontinued, withdrawal symptoms such as shaking, sweating, cramps and diarrhea can start within hours of last use.
<span>the average rate at which a species' genome accumulates mutations,
used to measure their evolutionary divergence and in other
calculations.</span>
The cell wall gives a rigid structure to the plant, it also controls what goes in and out
<span>D) intertidal zones, deep sea vents and salt marshes</span>
