Which of the following titles is most appropriate to the passage?A.Polarity Reversal: A Fa
Which of the following titles is most appropriate to the passage?
A.Polarity Reversal: A Fantastic Phenomenon of Nature.
B.Measurement of the Earth's Magnetic-Field Intensity.
C.Formation of the Two Poles of the Earth.
D.A New Approach to the Study or Geophysics.