Why is the first breath of a newborn the most difficult ?

If two parents who's blood types are both b produce a child that has blood type o, what can you say about the parent's genotybes? oa) one is ii ob) one is ibi oc) both are bi od) nothing, this is impossible

2. given that most biochemical (other than coal) rocks react with hydrochloric acid, what does that tell you about organisms?

Vessels draining the myocardium of the heart, open primarily ,into which chamber?