Which of the following was a lasting effect of the mining boom? 1. Nevada, Colorado, and South Dakota grew rapidly and gained statehood.
2. Many ghost towns still have hidden deposits of gold dust.
3. The gold standard is still in effect today.
4. Tourists can still view the golden spike at Promontory Summit today.

Martha participates in a research study in order to receive extra credit for her psychology class. when she arrives in the research office she is given a can of what looks and tastes like beer, but which actually contains no alcohol. in the adjoining room martha's classmate karen is also participating in the study. karen receives a can of alcoholic beer. if the experiment was designed to test the effects of alcohol on concentration, then who is exposed to the independent variable?