( 3 ) Lan guages have been coming and going for thousands of years , but in recent times there has been less coming and a lot more going. When the world was still populated by hunter - gatherers , small , tightly knit ( 联系 ) groups developed their own patterns of speech independent of each other. Some language experts believe that 10 , 000 years ago , when the world had just five to ten million people , they spoke perhaps 12 , 000 languages between them. 1. What is the main idea of the text? A . New languages will be created. B . People's lifestyles are reflected in languages. C . Human development results in fewer languages. D . Geography determines language evolution.