Question: Fact 1: Acar engine usually converts gasoline into motion and heat through combustion. Fact 2: Oxygen acts as an aid to combustion. Given the two facts above, what acts as an aid to a car engine converting gasoline into motion and heat?
OPTIONS:
- Energy.
- oxygen
- nitrogen
- helium
- argon
- energy
- burning
- sugar
Answer: oxygen

Question: Fact 1: High pressure systems cause clear weather. Fact 2: Most deserts occur in regions that typically have high atmospheric pressure. Given the two facts above, what usually has clear weather?
OPTIONS:
- hurricanes
- mild
- deserts
- less water
- autumn
- swamps
- rain forests
- Winter
Answer: deserts

Question: Fact 1: Bottleneck effect occurs when a population suddenly gets much smaller. Fact 2: Population growth is reduced by external migration. Given the two facts above, bottleneck effect can occur with ?
OPTIONS:
- external migration
- direct damage to the lungs
- Movement of an air mass
- competition
- if humans disturb bears
- competing for resources
- Plant growth is reduced
- Temperature changing
Answer:
external migration