Answer:
By breathing when oxygen enters the body it goes to alveoli and gas exchange occurs then carbon dioxide comes out of the the body
the enzymes joins to synthesize anew DNA
Explanation:
because each new DNA molecules is made of one good original new strand
It is because that's a place where no one lives so they're safe.
B, the independent variable because this is the one that is purposefully changed in an experiment to test the hypothesis.
