WILL MARK BRAINLIEST!

An experiment is performed to test the effect of three different types of water on the growth of a plant. The test is done by using tap water, distilled water, and carbonated water. Choose the statement below that describes the tap water in this experiment.

A. The tap water is a controlled variable for all plants.
B. The tap water is the control group for comparison.
C. Tap water is the only test condition that will cause changes in the dependent variable.
D. Tap water is one of the three test conditions of the independent variable, the type of water.

D. Tap water is one of the three test conditions of the independent variable, the type of water.

Explanation:

An independent variable is the part of a science experiment that is changed. Since you are changing the type of water, the independent variable would be the water. There are 3 types of water in this experiment, meaning the tap water is one of the 3 test conditions of the independent variable.

from my research i have to the conclusion that decomposers, such as fungi, bacteria and invertebrates, play a critical role in nutrient cycling and without them the earth's ecosystem may not support life as we know it. elements such as carbon, nitrogen and phosphorus exist in limited amounts on earth, although huge amounts of carbon are being released into the atmosphere from underground sources now by humans. it is still extremely important that other nutrients be retained by the process of re-use. decomposers are organisms that are able to chemically break down dead material and make these elements available for use by other organisms. without this breakdown of dead material, dead bodies would pile up. so decomposers also play a role in clean up also. without them, life might not continue as we know it and dead material would overwhelm the earth.    

coal is not sustainable because it will one day run out.