<h2>Right answer: It is used to measure long distances in space</h2>
A light year (
) is a distance unit that is approximately 
.
By definition it is <em>the distance that a photon would travel in vacuum during a Julian year (365.25 days) at the speed of light (299 792 458 m/s) at an infinite distance from any gravitational field or field magnetic.
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In other words:
It is the distance that light can travel in a year.
This unit is used to measure large distances in space. Therefore the correct answer is D.
Well right now there are issues such as unemployment, government corruption, crime, access of clean water, and energy shortages.
In the future there could be issues such as lack of better healthcare treatments and equipment and better education.
The correct option is C.
Sandstone is a type of sedimentary rock that is formed by physical weathering of parent rocks. It is usually made up of sand size particles of minerals, rocks, other organic materials and the cementing material that bind the sand grains together.
Sandstone can not be found as a chemical sedimentary rock because it is formed by mean of physical weathering and not by chemical reactions of the rock.
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