Jack always takes his dog out for a walk in the morning. Whenever Jack puts the leash on his dog, the dog gets very excited about going for a walk. In this scenario, the dog has learned to associate the leash with going for a walk through:.

What are objects called that have value in and of themselves as well as value as a means of exchange? custom commodity money currency simple money

What greek scientist created a screw to move water for irrigation?

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.