Which statement is true? The perfect cosmological principle is the basis for the oscillating universe theory.
The oscillating universe theory suggests that the universe will expand forever,
The perfect cosmological principle is the basis for the big bang theory.
The perfect cosmological principle is the basis for the steady state theory.

I'm thinking it's 2 you are asked to explain the earth's magnetic field. which is the best reply? 1. the earth's magnetic south is similar to the north pole of a magnet. 2. the earth's core has a strong magnetic charge similar to the south pole of a magnet. 3. the earth's geomagnetic south is similar to the south pole of a magnet. 4. the earth's magnetic charge is not centered at either pole; it varies based on location.