*Question*
Q: Fuels according to the law of what, can never actually be "consumed"; it can only be changed from one form to another? Choices: - use of energy - expansion of energy - difference of energy - conservation of energy A:
**Answer**
conservation of energy

*Question*
Q: The lungs perform gas exchange using air and what fluid, which is coming and going from the heart? Choices: - mucus - water - saliva - blood A:
**Answer**
blood

*Question*
Q: The paired bones of the skull are the palatine, zygomatic, nasal, lacrimal, inferior nasal conchae bones, and what else? Choices: - minilla - ventral - elongated - maxilla A:
**Answer**
maxilla

*Question*
Q: What percentage of all species that ever lived on earth have gone extinct? Choices: - 25% - 50% - 93 % - 99% A:
**Answer**
99%