Based on measurements of the expansion of the universe, of the position of galaxies, as well as of the cosmic microwave background radiation, the birth of the universe is said to (i) _______ 13.7 billion years ago, when the early cosmos was a dense gaseous fireball of plasma, with temperatures 100,000 times higher than (ii) _______ of the sun’s core. 10 microseconds after the initial explosion, the universe experienced a period of huge exponential (iii) _______ called cosmic inflation, allowing basic particles such as quarks and gluons to stop moving around willy-nilly without purpose and form strong bonds of protons and neutrons. 100 seconds later, as temperatures dropped even further, these protons and neutrons would form helium and other hydrogen composites in a period cissalled nucleosynthesis. Matter would (iv) _______ to a halt and stop moving, (v) _______ gravitational forces come into play, and after 380,000 years the first atoms would make their appearance.
(iv)______-
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