In DSM, nicotine dependence is included under the general definition of substance dependence.  The essential feature of Substance Dependence is a cluster of cognitive, behavioral, and physiologic symptoms indicating that the individual continues use of the substance despite significant substance-related problems.
Greenhouse Covering. Whether you're replacing existing greenhouse coverings or building a greenhouse you're sure to find the best greenhouse covering at FarmTek. Greenhouse glazing is the material that covers the greenhouse frame and the most widely used materials are polycarbonate and poly film.
Quick Answer. A greenhouse is an example of a microclimate. A greenhouse absorbs the heat of the sun and then releases it slowly over time. Greenhouses are used in areas where it is too cold to grow plants that require extra warmth. Continue Reading.