Answer: A
Explanation:
Our universe was born from the Big Bang about 13.5 billion years ago. ... Our solar system began forming about 4.6 billion years ago within a concentration of interstellar dust and hydrogen gas called a molecular cloud. The cloud contracted under its own gravity and our proto-Sun formed in the hot dense center.
The answer is B since you have to be able to prove/elaborate on the topic sentence
It stopped in 11,700 years ago
What do you need help with sir??
Answer:
The populations become adapted to different environments and eventually become so different that they cannot interbreed to produce fertile offspring.
Speciation is the evolution of one species into two different kinds, and when they become isolated, that is the final step, since they cannot interbreed any longer.