Q: _ allow water to penetrate the soil.
Options:
- (A) crawfish burrows
- (B) major threat to health
- (C) Deposition
- (D) bending light rays
- (E) earthworm homes
- (F) Exfoliation
- (G) termite burrows
- (H) Earthworm burrows
A: So, my chain of thought: Earthworm burrows help aerate soil, which is also good for plants. Aeration breaks up the soil and allows water to penetrate. Earthworm burrows allow water to penetrate the soil, which is good for plants. The answer is (H).

Q: Emphysema is often cause by exposure to:
Options:
- (A) high temperature
- (B) fog
- (C) Greenhouse gasses
- (D) rays or beams
- (E) hot steam
- (F) tobacco smoke
- (G) Pollution
- (H) incendiary people
A: So, my chain of thought: Lung cancer is most often caused by exposure to tobacco smoke. Many patients with lung cancer also have emphysema. Enphysema is often caused by exposure to tobacco smoke. The answer is (F).

Q: What powers sweat?
Options:
- (A) heat produced
- (B) The body's fuel
- (C) a gas in the air
- (D) hydration
- (E) When the water is hot
- (F) air cools
- (G) matter vibrating
- (H) Cooling vapors
A:
So, my chain of thought: Evaporation of sweat uses energy, and the energy comes from body heat. Energy is the body's fuel. When sweat is evaporated, the body's fuel is used. The answer is (B).