Final answer:
Nasal cannulas can be used for patients who breathe through their nose, mouth, or a combination of both.
Step-by-step explanation:
Nasal cannulas are commonly used in healthcare settings to deliver supplemental oxygen to patients who have difficulty breathing. While they are often used for patients who primarily breathe through their nose, nasal cannulas can also be used for patients who breathe through their mouth or a combination of both. The primary purpose of a nasal cannula is to provide a continuous flow of oxygen to the patient, regardless of their breathing patterns.