What is he different between the inner coastal plain and the outer coastal plain?

Which of the following would a historian most likely study to find data

Using mr smith and his id, identify two potential internal validity threats that might affect the a—b design. tell me how that threat might impact conclusions in the a—b design. note #1: you cannot use maturation (since i already did that one for note #2: there are some mr smith id threats that won’t have much impact in a single case design.

Which of these persons was a co-founder of twitter? eric schmidt jack dorsey tim cook paul alle