Q: What oily substance prevents the hair and skin of living things from drying out? Choices: - pus - progesterone - pancreatic enzymes - sebum A:
sebum

Q: Bromide is present in brines, which are naturally occurring solutions of what? Choices: - iron - calcium - magnesium - salt A:
salt

Q: Q: Diamond is extremely hard because of the strong bonding between ______ in all directions? Choices: - consistent atoms - hydrogen atoms - liquid atoms - carbon atoms A:
A: carbon atoms

Question: Q: Models may be physical, conceptual, or what else? Choices: - experimental - fundamental - theoretical - mathematical A:
Answer: mathematical

*Question*
Q: Acid rain is corrosive rain caused by rainwater falling to the ground through which gas? Choices: - sulfide dioxide - carbon dioxide - essential dioxide - sulfur dioxide A:
**Answer**
sulfur dioxide

(Q).
Q: What is at the center of our solar system? Choices: - the moon - earth - the Kuiper Belt - the sun A:
(A).
the sun