Answer:
The oxygen revolution happened about 2.5 billion years ago. ... Then oxygen started to accumulate in the atmosphere. Oxygen is toxic to anaerobic organisms and this increase in atmospheric oxygen killed much of the life that had evolved to this point generating a huge mass extinction.
Explanation:
Explanation:
Because it needs a place to hide and place it eggs.
Answer:
its B but i also think its D
Answer;
Low birth weight.
One of the most consistent and best documented effects of cigarette smoking during pregnancy is low birth weight.
Explanation;
Smoking during pregnancy has various effects on the fetus, causing a baby to be born early or to have low birth weight which makes it more likely for the baby to get sick and stay in the hospital longer.
Additionally; smoking during and after pregnancy is a risk factor of Sudden Infant Death Syndrome.
