I believe the answer is the weight of each tomato.
This is because the weight of each tomato depends on the amount of fertilizer (the independent variable/the thing being changed) added to each plant.
Magnesium Sulphate Monohydrate
Answer:
A. Food was turned into blood, and when it reached the heart it was mixed with air to make 'spirit.'
Explanation:
Galen believed a theory of pneuma. That is, he believed that blood contains "vital spirits" released into it by the brain.