Q: In the presence of oxygen, hydrogen can interact to make what? Choices: - carbon - helium - acid - water A:
water

(Question)
Q: Oxygenated blood is transported by what system? Choices: - skeletal - nervous - pulmonary - circulatory A:
(Answer)
circulatory

Ques: Q: During what time period did poor air quality become a problem? Choices: - Chernobyl disaster - coal industry boom - second world war - industrial revolution A:
Ans: industrial revolution

(Q).
Q: When food is scarce, starving cells secrete a molecule that stimulates neighboring cells to do what? Choices: - compete - hoard energy - die off - aggregate A:
(A).
aggregate

Ques:Q: Although it is not vital to humans, calcitonin is important for calcium homeostasis in adults of some species in what group characterized by backbones? Choices: - mammals - reptiles - invertebrates - vertebrates A:

Ans:vertebrates

Q: The nervous system is characterized by electrical signals that are sent from one area to another. whether those areas are close or very far apart, the signal must travel along this? Choices: - axial - hairs - tendons - axon A:
axon