Question: Fact 1: Mammals generate heat mainly by keeping their metabolic rate high. Fact 2: Aerobic exercise also contributes to the increased the metabolic rate. Given the two facts above, mammals can generate heat by?
OPTIONS:
- hibernation
- layers of fat
- perspiration
- aerobic exercise
- respiration
- exercise
- with their fur
- to stay warm
Answer: aerobic exercise

Question: Fact 1: High temperatures can cause an object to combust. Fact 2: Combustion generates toxic fumes. Given the two facts above, what can create toxic fumes?
OPTIONS:
- cigarettes
- High temperatures.
- smoking tobacco
- harmful substances
- fossil fuels
- chlorofluorocarbons
- Pesticides
- chemical reaction
Answer: High temperatures.

Question: Fact 1: Streams may start with runoff or water seeping out of a spring. Fact 2: Most water comes from precipitation. Given the two facts above, what do most streams start with?
OPTIONS:
- swamp vegetation
- heat produced
- loose dirt
- Decibels
- Veins and arteries.
- matter vibrating
- visible energy
- precipitation
Answer:
precipitation