Answer:
All gases are compressible. Depending on their state. Oxygen can be a gas, a solid or a liquid. Liquid oygen (very very cold) would not be compressible, solid oxygen (frozen) would not either but as a gas at standard conditions - room temperature and pressure - it can be compressed. For example, compressed oxygen is used in emergency vehicles to keep people alive if they are injured or sick. It is extremely flammable, almost explosive so no smoking near a compressed oxygen gas cylinder, OK?