Problem:OPTIONS:
- cloud cover
- Population size
- Pollution
- Pesticides
- rainfall
- risky population
- Climate change
- the environment

Fact 1: Population size influences the chances of a species surviving. Fact 2: Each species lasts for a time, sometimes surviving to the present and sometimes going extinct. Given the two facts above, what influences the chances of going extinct?
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A: Population size

Problem:OPTIONS:
- an external framework
- one celled organisms
- dust
- living animals
- deuterostomes
- spaceships
- blastoids
- footprints

Fact 1: An animal requires air for survival. Fact 2: The Moon has no atmosphere and no air. Given the two facts above, what cannot be found on the moon?
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A: living animals

Problem:OPTIONS:
- light bulbs
- waves
- wind
- headphones
- rivers
- coal
- motors
- viruses

Fact 1: Tidal energy can be used to produce electricity. Fact 2: Ocean thermal is energy derived from waves and also from tidal waves. Given the two facts above, what can be used to produce electricity?
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A: waves

Problem:OPTIONS:
- energy of moving objects
- chemical messengers
- the body's largest organ
- peace
- Thinking hard
- Blowing a whistle
- Electrical energy
- death

Fact 1: Blowing air into a whistle causes air to vibrate inside the whistle. Fact 2: Sounds are vibrations in air. Given the two facts above, what creates sounds?
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A:
Blowing a whistle