Question

select the word that means block or prevent. cerumen, or earwax, protects the sensitive inner ear from dirt and infection. if too much earwax collects, however, it can obstruct the ear canal, making it hard to hear. if that happens to you, dont stick anything into your ear canal. ask a doctor or nurse how to remove the wax safely.

Explanation:

The sentence "If too much earwax collects, however, it can obstruct the ear canal, making it hard to hear" shows that "obstruct" is used in the context of something (earwax) getting in the way (of the ear canal), which aligns with the meaning "block or prevent".

Answer:

obstruct