When does Miralda-Escude estimate the first star appeared？
A. 75 million years ago.
B. 14 billion years ago.
C. 14 billion years after the big bang.
D. 75 million years after the big bang.
How does the article suggest the matter that makes up the Earth was first spread through the universe？
A. Through expulsion from black holes.
B. Through the explosions of stars.
C. Hydrogen propulsion.
D. Theoretical balancing.
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