Sassafras root is still used to flavor traditional root beer, although since sassafras was banned by the U.S. Food and Drug Administration because of the carcinogenicity of its constituent safrole, most commercial recipes do not contain sassafras. Some commercial root beers do use a safrole-free sassafras extract.
There are usually 18 holes in a golf course; some have 9 holes or some multiplier of 9 holes. I have played at golf clubs with 9, 18, 27 and 36 holes. However, a standard round of golf at most golf clubs / courses involves 18 holes.
A standard round of golf consists of 18 holes. Most courses contain 18 holes; some share fairways or greens, and a subset has nine holes, played twice per round. Par-3 courses consist of nine or 18 holes all of which have a par of three strokes. Many older courses are links, often coastal.