Not surprisingly, given that tobacco dependence is largely a dependence on nicotine, certain forms of nicotine replacement therapy have been shown to be more effective at higher levels of dependence and it is in this area that most progress towards matching treatments is likely to be made in the future (Sutherland & Stapleton, 1994).
Typically, concrete is not considered polished before 400 grit, and it is normally finished to either the 800, 1500, or 3000 grit level. Stains and dyes are often applied to enhance polished concrete as well as other options such as scoring, creating radial lines, grids, bands, borders, and other designs.
Most concrete is made of a mixture of sand, gravel, cement and additives that provide strength. You can purchase many types of premixed concrete for stepping stones at most home improvement stores or you can mix your own concrete using cement, gravel, sand and water. To make stepping stones for a garden, many people simply use the standard premixed concrete that you can find at many hardware stores. Premixed concrete is very easy to use because you just add water to the mix according to manufacturer's directions. You can then pour wet concrete into molds and let it set.