Me with this i am stuck

what kind of small objects composes much of the universe

The question seems kind of squishy.

The smallest objects are also the most numerous in the
whole universe.  Those are the Hydrogen atoms.

The most numerous objects that are big enough for us to see
are the stars, but I'm not going to say that those are the answer.
Stick with me here, and follow my reasoning.

The Kepler space telescope is discovering so many planets
orbiting other stars outside our solar system, that it's beginning
to look like MOST stars have planets.

Stars are bigger.  Planets are smaller.  If most stars have planets,
then the most numerous objects that compose much of the universe
are the planets !  (plus maybe their moons too) 

Does this make any sense to you ?

Now I have to ask YOU a question:
Are there any choices for answers to this question
that you're not telling us about ?

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