1
Some explosions of stars are called ______..
2
Big Bang is an _______.
3
______ are grouped into clusters and superclusters.
4
When the _____ cooled, the simple elements formed.
5
Star explosions allowed rocky _____ to form.
6
______ gradually attracted matter.
7
Due to the high density and temperature, _________ expanded.
8
Due to gravity the first _________ were formed.
