What might be a reason why there are limited participation of minorities in clinical research?

What caused the settlement of more african americans in the mississippi alluvial plain region then in the ozark mountains region?

Which act was a response to three high-profile assassinations? a. the mailing of firearms act b. the national firearms act c. the gun control act d. the brady handgun violence prevention act

Why is mary salter ainsworth a central figure in psychology?