Pls help, ill give brainlist if u answer this :) help me

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?

What are the positive and negative aspects of rejection of vote?

How did china's location impact trade and its development?