I would say the answer is A I really hope this helps! :)
The answer is A: being familiar with different types of galaxies that exist in the universe
Longest to Shortest:
<span>across the diameter of the galactic halo - 200,000 light years
</span><span>across the diameter of the galactic disk - 100,000 light years
</span><span>from the sun to the center of the galaxy - 26,000 light years
</span><span>across the diameter of the central buldge - 20,000 light years
</span><span>through the disk from top to bottom - 1,000 light years.</span>
When tiny ice crystals in clouds stick together to form snowflakes, the result is snow. If enough crystals form a clump, they'll become heavy enough to fall to the ground. When temperatures are cold and moisture in the form of tiny ice crystals exists in the atmosphere, snow forms.
