What is waste water treatment ?
“The major aim of wastewater treatment is to remove as much of the suspended solids as possible before the remaining water, called effluent, is discharged back to the environment.”
My source is from www.usgs.gov
Answer:
The color of the birdfeeders
Explanation:
Independent variable is the variable in the experiment that is changed, so the only thing changed in this experiment is the colors of the bird feeders