How did the Song improve upon the Tang version of the civil service system?

How did the people of latin america come to speak the language of spanish

Chen's research team randomly assigned some newborns and their mothers either to a breastfeeding promotion group (where breastfeeding was encouraged, but not required) or to a normal pediatric care group (where breastfeeding was neither encouraged nor discouraged). which research method did they use?

'nepal have varied vegetation as climate and landforms'. justify the statement