What are the 4 sources of dissolved gases

Which mantle is under the crust the upper mantle or the lower mantle i think it's upper let me know if i'm right

When new rock is added to an oceanic ridge, the magnetized strips on either side of the ridge are evidence of sea-floor spreading. this is because the rocks on the two sides of the ridge o are equal in width and in polarity are polar opposites oare magnetized vary in width but are equal in polarity

Organize the word parts according to where they appear in a medical term.