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.
Courses differ. A round of 18 holes obviously takes longer than nine holes. Par-3 courses (total par 54) generally take less time to complete than a regulation course (par 70 to 72). Course yardage matters as well: Courses with long par-5s (550-600 yards) and 4s (400-465 yards) generally take a little longer than courses with shorter holes.