In medicine, what does the r in mri stand for? radiation

MRI mean Magnetic Resonance Imaging.
This is a big machine that detects tumors, bleeding and abnormalities in the Brain. :)
I hope this has helped you haha :)

The answer is atmosphere. there are four spheres of the earth: 1. geosphere (from greek word 'geo' = ground), 2. hydrosphere (from greek word 'hydro' = water), 3. biosphere (from greek word 'bio' = life), and 4. atmosphere (from greek word 'atmo' = air). a magnetosphere is a region of space around astronomical objects controlled by the magnetic field of that object. through the process of elimination, since lightning is present in the air, it can be found in the atmosphere.

I’m not really sure