Adding earthworms to a compost pile typically increases the rate at which the organic
matter in the pile decomposes. A learner wonders whether adding other organisms to the
compost pile will have a similar effect on the rate of decomposition. She decides to an-
swer this question by performing an experiment.
Formulate a valid hypothesis that the learner could test in her experiment.
Based on this hypothesis, identify the independent variable and dependent variables for the
learner's experiment.
..
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Compost