Need help answer all three to get brainliest

On average, being married has a(n) effect on happiness.

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.

Including place names directions and distances describe a route harriet tubman was likely to have followed from her slave home near bucktown to philadelphia