This is my attempt to explain air pressure in ductwork. This video is part of the heating and cooling series of training videos made to accompany my websites... This is my attempt to explain air pressure in ductwork. This video is part of the heating and cooling series of training videos made to accompany my websites... Skip navigation
Medical marijuana refers to the use of the Cannabis plant as a physician-recommended herbal therapy as well as synthetic THC and cannabinoids. So far, the medical use of cannabis is legal only in a limited number of territories, including Canada, Belgium, Australia, the Netherlands, Spain, and several U.S. states.
What is marijuana. Marijuana refers to the dried leaves, flowers, stems, and seeds from the hemp plant, Cannabis sativa. The plant contains the mind-altering chemical delta-9-tetrahydrocannabinol (THC) and other related compounds.Extracts with high amounts of THC can also be made from the cannabis plant (see  Marijuana Extracts ). Marijuana refers to the dried leaves, flowers, stems, and seeds from the hemp plant, Cannabis sativa. 2  The plant contains the mind-altering chemical delta-9-tetrahydrocannabinol (THC) and other related compounds. 3  People use marijuana by smoking, eating, drinking, and inhaling it.