Carbonic anhydrase is found in the blood's erythrocytes and slows the dissociation of carbonic acid in the blood

Croup is a:

A) bacterial infection of the upper airway. B) bacterial infection of the lower airway. C) viral infection of the lower airway. D) viral infection of the upper airway.

For periodontal debridement, the INR should be < _____

Fill in the blank(s) with correct word