People with COPD must breathe harder to pull oxygen in and push carbon dioxide out of their lungs.
(People with COPD; must breathe harder; to pull oxygen in and push carbon dioxide out of their lungs) Context(People with COPD must breathe harder,List([0, 36))):(People with COPD; must breathe harder to pull; oxygen; in)
People with COPD must breathe harder,List([0, 36))
People with COPD People with COPD
must breathe harder must breathe harder to pull
to pull oxygen in and push carbon dioxide out of their lungs
oxygen in