q: What has woody stems covered with bark?
Options:
- (A) sunflowers
- (B) Newton
- (C) ferns
- (D) seaweed
- (E) Most plants
- (F) palm trees
- (G) evergreens
- (H) orchids
a: (G)... Explanation: Trees have woody stems covered with bark. Orange trees are evergreen trees. Evergreens have woody stems covered with bark. That's why the answer is (G).

q: Harm to the respiratory and circulatory systems can come from
Options:
- (A) Greenhouse gases
- (B) hydrocarbons
- (C) Sulfur dioxide
- (D) nitrogen oxides
- (E) burning coal
- (F) fossil fuels
- (G) emissions
- (H) Greenhouse gasses
a: (D)... Explanation: Air pollution harms the respiratory and circulatory systems. Nitrogen oxides cause air pollution. Nitrogen oxides harms the respiratory and circulatory systems. That's why the answer is (D).

q: What conserve body heat with their hair or fur?
Options:
- (A) foxes
- (B) snakes
- (C) goats
- (D) whales
- (E) dogs
- (F) cats
- (G) humans
- (H) lizards
a: (A)... Explanation: Mammals conserve body heat with their hair or fur. Mammals include rabbits, foxes and coyotes. Foxes conserve body heat with their hair or fur. That's why the answer is (A).

q: What occurs in animals as they respond to changes in their habitat?
Options:
- (A) starvation
- (B) evolution
- (C) arousal
- (D) relocation
- (E) resistance
- (F) dependency
- (G) Leptospirosis
- (H) Movement
a:
(B)... Explanation: Evolution occurs in response to a change in the environment. Animals react instinctively to changes in their environment. Evolution occurs in animals as they respond to change in their habitat. That's why the answer is (B).