Problem:OPTIONS:
- A yellow star
- Time and energy
- energy of moving objects
- A natural satellite
- flow of electrons
- An artificial satellite
- A red star
- hydrogen and oxygen

Fact 1: The gravitational pull of the Moon on Earth 's oceans causes the tides. Fact 2: Planetary moons are natural satellites. Given the two facts above, the pull of what on the Earth's oceans cause the tides?
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A: A natural satellite

Problem:OPTIONS:
- h2o
- brain
- hard outer covering
- fur and fat
- protective bony armor
- salt and pepper
- epidermis and dermis
- deoxyribonucleic acid

Fact 1: Skin is used for protecting the body from harmful substances. Fact 2: Skin is comprised of two layers, the epidermis and dermis. Given the two facts above, what protects the body from harmful substances?
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A: epidermis and dermis

Problem:OPTIONS:
- that metal
- muscles
- Weight
- stomach
- mammals
- atoms
- ligaments
- sweating

Fact 1: Shivering occurs when many muscles contract a little bit all at once. Fact 2: Almost all birds use shivering as a short term adjustment to the cold. Given the two facts above, what can contract a little bit all at once as a short term adjustment to the cold?
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A: muscles

Problem:OPTIONS:
- hormones
- amoebae
- weight
- motion
- an object
- voltage
- symptoms
- motility

Fact 1: Phase changes do not change mass. Fact 2: Weight and mass mean the same thing. Given the two facts above, phase changes do not change?
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A:
weight