Question

trisha bell fell off her bicycle and scraped off the superficial layers of skin on her knees. this type of injury is known as a/an select fissure abrasion ulcer bulla

Explanation:

An abrasion is a type of injury where the superficial layers of skin are scraped off due to friction, like in a fall. A fissure is a crack, an ulcer is an open - sore, and a bulla is a large blister.

Answer:

abrasion