This happens in the second trimester. I'm pretty sure that's the right answer. I hope it helps!
All of the above is the right answer
Answer:
If air is polluted, the air contains harmful gases and health status become poor. In contrary, if environment is clean and fresh, the health will be good. Therefore, health, population and environment education are interrelated in physical aspect. Health, population and environment are integrated terms.
Answer:
The baby starts breathing
Explanation:
While in the womb, a fetus has its oxygen delivered to it, and the waste products removed (all via the mother's bloodstream), so there is no reason to separate all the chambers of the heart while still in the womb.
However, once the baby is born and it is breathing, the chambers need to differentiate in order to allow the blood to reach the lungs, and the oxygenated blood and deoxygenated blood do not mix.
