sentences: an animal / bacterium requires oxygen for survival / to breathe
docs: oxygen is necessity_for_life. oxygen_crisis is oxygen_catastrophe. oxygen_holocaust is oxygen_catastrophe. snorkel is breathing_device. mammal is air_breathing_vertebrate. sivapithecus is mammal. dinosaur is air_breathing_vertebrate. all_mammals_breathe_air_and has lungs oxygen_therapy is oxygen. oxygen_mask is breathing_device.