答案:Thereare generaily two major factors that causesemantc change in the living languages.A isexralinguistic factors (histonical reasoneass reason and psychoiogical reason)T isdinguistic factors (shortening, the influx of borrowing, and analogy). OR:As time passes. changes keep taking place in society and our daily life.New concepts,ideas and new things emerge continuously.Man has come to know more and more about the world around. All this is reflected in language.The change of meaning may also be caused by internal factors within the language system.