Questions remain about gravity (Why is it so weak?)
Because if were any stronger, the Universe would have contracted back to nothing eons ago.
antimatter (Why is there so little of it?)
To keep them from causing a chain reaction and destroying the Universe.
and dark matter, the mysterious and invisible substance that makes up nearly a quarter of the universe (What particle might be responsible?).
Why, the dark particle, of course.
“Dark?”
Dark this and that, but is “dark” defined?
What? They can't see the dark matter? Try reading "Invisible Man" by Ralph Ellison! That will explain it to all you white scientists that don't want to see the dark matter! Racists, all of you!