1)what volume of air was breathed out during one normal exhalation 2)how many times did exhalation take place during one minute of normal breathing
3)how many times did deep exhalation take place in 30 seconds ​

Chronic obstructive pulmonary disease (copd) makes it difficult for the respiratory system to deliver oxygen to the lungs. the scientist wants to use a computer simulation to model how copd affects heart rate and respiratory rate during exercise. she will compare the results of the simulation to the results she gathered in her previous study. which of the following would be an appropriate dependent variable for the new study?