Which describes the dependent variable in an experiment

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

How do plants obtain more sunlight a.) they lean towards the light b.)they grow straight up c.) they only live in sunny areas, like the tropics d.) they stay low to the ground

The big bang theory suggest that the universe is about - 300 million years old - 4.6 billion years old - 30 billion years old - 13 billion years old