Because it's vital to the survival of all species, not just human, that we have resources such as food and water. Also that those resources be clean and healthy. We also need to manage resources such as oil to make sure there are fewer wars like the ones happening in the Middle East. If you need anything else just message me.
If the heat is applied by open flame, the slow boil-off of alcohol vapor can burn off without exploding or igniting the leaf bath.
Answer: The blood vessels in the umbilical cord, the fetus receives all the necessary nutrition, oxygen, and life support from the mother through the placenta.
Explanation:
Scientists prove their hypothesis is true about Scientists can never "prove" their hypotheses are true, because some future experiment, possibly using new technology not currently available, might show the hypothesis to be false after all.