How does the design of your experiment control for outside factors that may affect the results?

Which of the following is an example of a tissue on the digestive system a. the stomach b. smooth muscle that lines the stomach c. nerve cells in the stomach d. enzyme molecules in the stomach

Classify the structures as homologous or analogous, depending on their structure and function.

Which of the following can be reduced by the use of renewable energy sources? a. social costs b. economic costs c. environmental costs d. all of the above select the best answer from the choices provided a b c d