Pneumonia is a leading cause of death.
A placebo is kind of a "fake" treatment but, typically the person receiving a placebo is unaware it has no medical effect on them so they believe they are feeling better. For example, a lot of anxiety meds are placebos and people don't know so their brain tricks them into thinking they are feeling less anxious. This could be used in experiments where a group believes they are affected to see how they react
The respiratory system works with the digestive and circulatory systems to make cellular respiration possible. During cellular respiration, your cells use oxygen and glucose to release energy. Carbon dioxide is a waste product of the process. Carbon dioxide must be removed from cells.
Info from: Google lolz.
I mean there is a lot of evidence that evolution has happen but i think if someone were to say it was false they would be getting into a religious beliefs. So I would say if you are using evidence than no it cannot be proven false. Hope this helps(;