________ is an enzyme that breaks down collagen

When the fire reaches a state where sufficient oxygen, fuel, and radiant feedback are available to prevent self-extinguishment, it has achieved what benchmark?

A) Established burning B) Flashover C) Backdraft D) Smoldering phase

Each type of tank truck is different but in general, an emergency shutoff is located ____.

A. on the dashboard B. underneath the tank C. behind the driver's side of the cab D. behind the passenger's side of the cab