<span>He is at an increased risk for sudden infant death. Since he is sleeping on a mattress that might inhibit his breathing, as well as having respiratory issues that might do the same (along with parents who are smoking, which will only inhibit proper respiration further), he will need to be constantly checked to make sure he is sleeping properly.</span>
I think that the answer is 12 billion. So sorry if I am not right.
In ancient times, people classified plants and animals by use. Like for plants they are being classified as beneficial or harmful. While for animals, they are classified as domestic animals, wild animals, creeping animals, flying animals, and sea animals.