Ques and Ans: What is a source of drinking water?
Options:
- (A) ice expanding in rock openings
- (B) helping to prevent floods
- (C) industrial runoff
- (D) it helps plants in growing
- (E) Water seeping out of a spring
- (F) salt water
- (G) polluted water
- (H) Something with a head, thorax, and abdomen
(E)
Logic chain: Streams may start with runoff or water seeping out of a spring. Lakes and streams are sources of drinking water. Water seeping out of a spring is a source of drinking water.

Ques and Ans: _ carry signals that control sexual development and reproduction.
Options:
- (A) photons
- (B) sex hormones
- (C) nerves
- (D) Most plants
- (E) organs
- (F) orchids
- (G) animals
- (H) insects
(B)
Logic chain: Sex hormones are chemical messengers that control sexual development and reproduction. Chemical messengers carry signals from one nerve branch to another. Sex hormones carry signals that control sexual development and reproduction.

Ques and Ans: What do most people need at least a little of every few days to survive?
Options:
- (A) NACL
- (B) UV
- (C) mL
- (D) oxygen
- (E) corn
- (F) H20
- (G) rest
- (H) Hydrogen
(F)
Logic chain: Most people can survive only a few days without water. Water is everywhere H20. Most people can only survive a few days without H20.

Ques and Ans: Damaged dna might benefit from:
Options:
- (A) resistance
- (B) cellular repair
- (C) mutagens
- (D) UV rays
- (E) recovery
- (F) radiation
- (G) Electrical energy
- (H) flow of electrons
(B)
Logic chain:
Cells have multiple repair mechanisms to fix mutations in DNA. And if the damaged DNA is duplicated, it causes mutation. Cells have multiple repair mechanisms to fix damaged DNA.