Author Question: The average length of a period during which a given magnetic field polarity exists is about A) ... (Read 45 times)

sarasara · **on:** Jul 14, 2018

The average length of a period during which a given magnetic field polarity exists is about

A) 10,000 years.
B) 100,000 years.
C) 500,000 years.
D) 1,000,000 years.

Question 2

Which of the following soil horizon designations is i the correct sequence from the surface to the bedrock?

A) O, E, C, B, A
B) A, B, C, O, R
C) S, O, I, L
D) O, A, E, B, C