[Q] What can slowly dissolve carbon in sedimentary rock?
Options:
- (A) hydrocarbons
- (B) acetic acid
- (C) precipitation
- (D) evaporation
- (E) rivers and streams
- (F) puddles
- (G) ponds
- (H) nitrogen
[A] Here's my solution: Flowing water can slowly dissolve carbon in sedimentary rock. Rivers and streams are bodies of fresh, flowing water. Rivers and streams can slowly dissolve carbon in sedimentary rock. The answer is (E).

[Q] What have humans have collected and grown for food for thousands of years?
Options:
- (A) sunlight
- (B) fungus
- (C) bread
- (D) salmon
- (E) fungi
- (F) dust
- (G) plants
- (H) edible
[A] Here's my solution: Humans have collected and grown mushrooms for food for thousands of years. Mushrooms are also fungi. Humans have collected and grown fungi for food for thousands of years. The answer is (E).

[Q] What kind of animal sometimes gets hiccups?
Options:
- (A) mammals
- (B) fur seals
- (C) fish
- (D) goats
- (E) humans
- (F) insects
- (G) worms
- (H) dogs
[A] Here's my solution: Mammals breathe with the help of a diaphragm. Hiccups are a result of spasms of the diaphragm. Mammals sometimes get hiccups. The answer is (A).

[Q] Organisms rely on a relatively narrow range of what?
Options:
- (A) Decibels
- (B) water
- (C) food
- (D) relativity
- (E) acidity
- (F) spectrum
- (G) balance
- (H) Light
[A]
Here's my solution: All life relies on a relatively narrow range of pH, or acidity. All organisms have a life-span. Organisms rely on a relatively narrow range of acidity. The answer is (E).