six-speed automatic transmission six-speed manual transmission six-speed transmission six-step six-step process six-story six-string six-thirty six-time six-time world six-way six-week six-wheeled six-year six-year absence six-year old six-year period six-year term six-year-old six-year-old boy six-year-old girl six-year-old son six-year-olds sixer sixers sixes sixes and sevens sixfold sixpack sixpence sixsmith sixt sixteen percent of sixteen year old sixteen years ago sixteen years later sixteen years of sixteen years of age sixteen years old sixteen-year-old sixteenth sixteenth amendment sixteenth and seventeenth sixteenth birthday sixteenth centuries sixteenth century sixteenth day sixteenth edition sixteenth periodic sixteenth president sixteenth studio sixteenth year sixteenth-century sixth sixth album sixth amendment sixth amendment right sixth and final sixth and final season sixth and ninth sixth and seventh sixth anniversary sixth annual sixth army sixth aspect sixth avenue sixth biggest sixth book sixth card sixth century sixth cervical sixth chakra sixth chamber sixth chapter sixth child sixth circuit sixth class sixth coalition sixth column sixth commandment sixth committee sixth company sixth conference sixth congress sixth consecutive sixth consecutive year sixth country sixth day sixth decade sixth dimension sixth directive sixth district sixth division sixth doctor sixth dynasty sixth edition sixth element sixth environment sixth environmental