Explain how seismic waves are used to determine composition, thickness and density of the interior of the Earth (write 2-3 sentences)

Explanation:

Seismic waves are elastic waves that are able to propagate within the subsurface.

The travel - time to depth expressed in form of velocity is used to determine the composition, thickness and density of the interior of the earth.

the menstrual cycle – higher tier. negative feedback mechanisms affect the production of hormones in the menstrual cycle. oestrogen also stimulates the release of lh (luteinising hormone) from the pituitary gland, which in turn controls the production of progesterone.