Wendy is investigating differences in cardiovascular health between children who are involved in extra-curricular activities and those who are not. she decides to investigate only children who are average height and weight, with no existing heart conditions and no family history of obesity. wendy has employed which method for controlling the extraneous variable in her study?

Agroup of anthropologists from the future want to study the culture and society of the twenty-first century. they cannot find any written documentation of this time period, so they must conduct an archaeological excavation.identify the artifacts, features, and ecofacts they will find during their fieldwork. what will these items tell the anthropologists about our culture and society?

Why does the supreme court only listen to a small percentage of cases every year?

What does one prolonged blast and one short blast mean?