Why did the silurian period end? what changed?

Although this may be the opposite of what you think i will say it anyway. you were brought into this world for a reason and you still have soo much ahead of you. not everybody has an opportunity of living a great life, but it doesn’t give you a reason to end everything. somebody in the world loves you, and imagine what you would do to them if you left forever.

Earthquake waves that vibrate from side to side and up and down only through solids are known as "seismic waves."hope my answer has you : )

The answer is    d.  central highlands