Hereditary illnesses, or causes that are uncontrollable like age
peer group and alcohol/other drug use
i think
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.
Watch your calorie intake and you'll lose weight fast
Explanation:
Measurement system, any of the systems used in the process of associating numbers with physical quantities and phenomena. Although the concept of weights and measures today includes such factors as temperature, luminosity, pressure, and electric current, it once consisted of only four basic measurements: mass (weight), distance or length, area, and volume (liquid or grain measure). The last three are, of course, closely related.