The pH scale measures how basic or acidic a substance is, and it ranges from 0 to 14. On the pH scale, a pH of 7 is neutral, less than 7 is acidic and higher than 7 is basic.
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A. looking for ways to improve the quality of water
Answer: i would say the independent variable is the soil and the control variable is the seed because it stays the same in all of them to better understand the experiment while the dependent variable is the fertilizer.
Explanation: i am not completely sure but maybe someone else can also answer to verify it first
