Ohannes wants to know whether soil, water, or both are needed for plant growth. he chooses to conduct experiments on a willow tree for five years to answer his question. how can his experimental methods be changed to improve his experiment?

She can plant a plant in one pot full of dirt and not water the plant to see if it is neccesary

Then she can plant a plant in a pot of nothing but water and see if the plant grows well

then she can plant a plant in a pot of both adding water to the soil.

In an expiriment you need to change the vairables to see if the results change,and,then reocrd your results.

false because ozone (o3) depletion does not cause global warming, but both of these environmental problems have a common cause: human activities that release pollutants into the atmosphere altering it.

global warming is caused primarily by putting too much carbon dioxide into the atmosphere when coal, oil, and natural gas are burned to generate electricity or to run our cars.

explanation: