Final answer:
The positive-pressure respirators from the options provided are atmosphere-supplying respirator, self-contained breathing apparatus, and powered air-purifying respirator.
Step-by-step explanation:
The positive-pressure respirators from the options provided are:
- Atmosphere-supplying respirator
- Self-contained breathing apparatus
- Powered air-purifying respirator
Positive-pressure respirators work by supplying clean, filtered air to the user, creating a higher pressure inside the mask compared to the surrounding environment. This prevents contaminated air from entering the mask.