Answer:
Before mountain building occurred, the area was underwater.
Explanation:
Through excavation, fossils that are of marine animals are often found high on mountain ranges. This seems weird from today's perspective, as marine animals can only be found in ocean waters, and there is no way they can travel on land and upon the mountains. Earth has changed a lot throughout history though, so such occurances are actually not that weird.
The mountains in Pennsylvania are such a place, with an abundance of marine fossils. When we look at the geological past of what is now Pennsylvania we can easily see why this is the case. The whole area was actually underwater for millions of years. This was the case before mountain building occurred here when part of the ocean floor raised high above the surface of the water and created land. As the crust was going up, the fossils on it went up as well.
Electronics is the best answer.<span />
Topographic maps use contour lines to show elevation.
Topographic maps, often called "topo maps," feature contour lines to portray the shape and elevation of the land.
Contour lines (lines of equal elevation) that are close together indicate steep terrain, while lines that are far apart indicate flat terrain.
Such maps also usually portray both natural and artificial features. They show and name natural land formations such as mountains, valleys, plains, lakes, rivers and vegetation. They also identify particular man made features such as roads, boundaries, transmission lines and major buildings.
It travels from the Gulf of Mexico and brings warm water to the Atlantic Ocean up the east coast of the us
