What is one positive about aquaponic and hydroponic systems? They can be used for drinking water.
They are expensive.
They can be scaled.
They are difficult to maintain

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

Why has two different alleles for the same trait?

Everything in the universe originated from a single point. how was it possible for everything in the universe to have occupied a single point in space?