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How do you add all of the slides in different PowerPoint presentations together? How do you keep them formatted the way they were originally designed? Watch this video to learn how.

Tsunami: why and where they originate and propagate.  A trip through the Earth's history from its formation to the present tectonic motions causing earthquakes and tsunamis. 

The evolution of the peppered moth over the last two hundred years has been studied in detail. Originally, the vast majority of peppered moths had light colouration, which effectively camouflaged them against the light-coloured trees and lichens which they rested upon. However, because of widespread pollution during the Industrial Revolution in England, many of the lichens died out, and the trees that peppered moths rested on became blackened by soot, causing most of the light-coloured moths, or typica, to die off from predation. At the same time, the dark-coloured, or melanic, moths, carbonaria, flourished because of their ability to hide on the darkened trees.