The correct hierarchy would be
-<span>A solar system is a collection of planets, their moons, and other objects in orbit around a central star.
</span><span>-A galaxy refers to all existing matter, energy, and space that is held together by gravity</span>
1 kg=100000 cg
2 kg=200000 cq
If mass is the quantity then kg is the S.I
2 kg=2kg
Significant digits show the precision of measurements and calculations
I believe it would be a musical note