Sentences of a paragraph are given below in jumbled order. Arrange the sentences in the right order to form a meaningful and coherent paragraph.
A. This cooled off into darkness after a few million years.
B. The first time was when the universe began its existence as a glowing fireball.
C. In the modern scientific story, light was created not once but twice.
D. The second time was when the cold material condensed into dense nuggets and ignited to become the first stars.