So boys this question is for you... There is this boy I really like and I am pretty sure he likes me too and we kept texting like seriously ALOT and then all of a sudden like about a month ago he started only texting me a tiny bit and every thing he said was one word and I am pretty sure I didn't do anything and this is kinda stressing me out is there a reason he is barely talking to me (PLS ANSWER QUICKLY)

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?