What is a light-year?
a) the distance light travels in one earth year
b) the distance light travels from the sun to the earth
c) the time it takes to travel across the universe
d) the distance the light travels in one orbit of the moon

The answer is (a)

Explanation:

a light year is a unit of astronomical distance equivalent to the distance that light travels in one year, which is 9.4607 × 1012 km (nearly 6 trillion miles).

The answer is A

Explanation:

I took the 4.06 quiz: Galaxies and got 100%

:3

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.