Science help!!!?

Question

1. At what other times, besides when diving, do people need portable oxygen supplies?
for this one I know --- in the hospital, under the ground, in industries, when you go to other planet
what else? I need 3 more

2. Divers lungs are squeezed by water pressure. What other body parts might also be affected?
I think all of them but how? what do you think?

3. What are some other uses for compressed air?
I don't know this one.

Please help. You can answer any of them.

Answer 1

1. In oxygen deficient atmospheres - in areas where hazardous chemicals have displaced air.

In certain confined spaces where there is a lack of oxygen (sewers)

In high altitudes (used by mountain climbers).

2. Bones are crushed by water pressure. Ears are subject to water pressure

3. Compressed air is used to air tires on bicycles, cars, trucks, etc...

Used to power certain equipment where hydraulic pressure is not applicable

Answer 2

1. Firefighters

2. Brain, Blood

3. Cleaning out computers, weapons (cannons)