How are the spiral arms related to the disk?

Once a woman attains puberty, her overuse mature and release one egg per ovarian cycle. which hormone stimulates this event?

Why are fossils not found in igneous rocks? igneous rocks are made from cooling of lava or magma. igneous rocks are found too deep underground. igneous rocks are too dark in color to contain fossils. igneous rocks are too dense to contain fossils.

How does science influence the decisions made about social, economic, and political issues?