Hey, can someone help me out <3

Brainliest to who answers! what will always cause a supply curve to shift to the left?

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?

No renewable resources are natural resources that are limited in supply and cannot be replaced as quickly as they are used.(true or false asnwering) a.true b.false