The average corn yield per acre has during the last forty years.

Mario performed an experiment to determine if photosynthesis was affected by the amount of light that a plant received. what could he have done to increase the validity of his data? reduce the number of plants. remove the 1 hour group. add a 0 hours control. measure the oxygen in liters

9. wind power creates pollution. water air soil noise

When is your respiration rate likely to change? a. when your intestines are digesting b. when your cells have too much glucose c. when your cells need more oxygen d. when your liver is working after a meal