<span>Landforms include striations, cirques, glacial horns, arêtes, trim lines, U-shaped valleys, </span>roches moutonnées<span>, overdeepenings and hanging valleys. These are all created by Glaciers!
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The two things that must exist for an electric current to be produced are:
An electric potential between two bodies and a conducting path joining the bodies.
This comes from the fact that when there is a potential difference there is an electrical field and hence a force that makes some free charges to move in the conductor. For this reason, there's an electrical current.
The line in which waves that are moving together are all in the same phase is referred to as the wave front.
For example, in a series of waves, all of the crests that are in a single line make up a single wave front. This is the case for every set of particles at the same specific point in a series of waves.
Telescope magnifies light coming from distant objects.
