Refrigerant R-12 was to be phased out as manufacturers switched systems to the environmentally friendly but more expensive GHG. Refrigeration repairmen consulted their forecasting models and unanimously concluded that they should stockpile R-12 while it was still affordable. These forecasting models could be classified as

Most sociologists agree that: a. culture is central in shaping gender roles, but only in preliterate societies. b. biological factors have some influence, but cultural factors are more important determinants of gender roles. c. biological factors are influential in determining gender roles, but only in industrial or complex societies. d. biological factors only explain differences between men and women with regard to aggression and disease. e. there is no difference between the influences of culture or biology on the development of gender roles, as they are unpredictable.