Almost a quarter, or approximately a quarter of the matter in the universe, is stuff that's invisible.
Presque un quart ou approximativement un quart de la matière de l'univers, demeure invisible.
Almost a quarter, or approximately a quarter of the matter in the universe, is stuff that's invisible.
Presque un quart ou approximativement un quart de la matière de l'univers, demeure invisible.