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Three batteries (AAA, AA and PP3), isolated on white background
Pile of baking soda on white background
Litmus strips for measurement of acidity
Scientist working colored litmus paper in hand in a lab, first-person, on a light background research lab, chemist in the lab examines a sample of contamination
Measure soil with digital device. Green plants and woman farmer measure PH and moisture in the soil. High technology agriculture concept.

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