Problem:OPTIONS:
- engines
- forces
- keratin
- Glass
- muscles
- fur
- oil
- sweat

Fact 1: Athermal insulator slows the transfer of heat. Fact 2: Materials like glass and wood are electrical insulators and thermal insulators. Given the two facts above, what can slow the transfer of heat?
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A: Glass

Problem:OPTIONS:
- temperature changes
- to leave the egg
- fertilization
- competition
- it needs them
- to feed
- permineralization
- to heal themselves

Fact 1: Sperm had to swim from male to female reproductive organs for fertilization. Fact 2: Male gametes are called sperm. Given the two facts above, why do male gametes swim from male to female reproductive organs?
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A: fertilization

Problem:OPTIONS:
- major threat to health
- remains of prehistoric life
- in the frog family
- running and lifting
- competing for resources
- warm-blooded
- objects that have mass
- graptolites

Fact 1: Amphibians are the first true tetrapods, or vertebrates with four limbs. Fact 2: All frogs are amphibians. Given the two facts above, the first tetrapods were?
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A: in the frog family

Problem:OPTIONS:
- light waves
- sound waves
- guitar
- friction
- chemical changes
- kinetic energy
- mechanical
- violinist

Fact 1: Plucking a string can cause that string to vibrate. Fact 2: For example, sound is a wave of vibrating air. Given the two facts above, what results from plucking a string?
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A:
sound waves