The anti-federalist protected the rights of the constitution and argued with the federalist against the expansion of national power.
The answer is a Natural Experiment.
A natural experiment takes place in natural settings and are used when independent variables can't be manipulated directly for ethical/practical reasons, so in this case the toddlers playing. Any effect observed happens naturally. They aren't seen as true experiments as the independent variable (toddlers playing) hasn't been changed deliberately to see effect on dependent variable (aggressiveness).
Answer:
I think it's A Preterm infants reach motor milestones later than do full-term infants
Explanation:
Their culture and what they celebrate
