0 any of the spaces inside the head that are connected to the back of the nose
1 the sinoatrial node (= tissue in the heart responsible for the heart's rhythm):
The electrocardiogram will confirm sinus bradycardia.
2 any of the hollow spaces in the bones of the head that open into the nose
We can complete it step by step however long the road is and it can't be completed however short the road is if you don't even mark your footprint.