What type of resource does the data in the chart represent?

Experiment to investigate effect of medication on levels of stress in males and females. dependant variable?

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 agreement did britain and the united states make in the treaty of 1818