The answer to this is C. Industry. It's the only man made factor.
So by looking at the seismic waves from earthquakes the scientist learned about the crust and the mantle but they also learned about the outer and inner core. To do this you have to look at a different kind of waves, the S (secondary waves) waves that also get released by an earthquake.
Plants have a cell wall and chloroplasts; animal cells do not have either
Hope this helps : )
<span>When the landmasses are again collected together in a specific area
The Pangea theory supports the theory of plate tectonics because it is based on the idea that all the present continents were one super-continent. For reasons still unknown, the super-continent got separated and created separate smaller continents. This theory also supports the fact that this movement will continue until the day arrives when all the smaller continents will again merge in a different configuration to create another super-continent. </span>
