Read the following statements carefully:
1.Scientists have put the Stephen Hawking theory to its most rigorous test to date, saying dark matter is not made up of primordial black holes smaller than a tenth of a millimetre.
2.About 85% of the matter in the universe is believed to be made up of dark matter.
3.Its gravitational force prevents stars in our Milky Way from flying apart.
Which of the above statements is/are correct?