Problem:OPTIONS:
- moon
- decreased differentiation
- earth's revolving
- the ocean
- Physical weathering
- colors of the spectrum
- gravity
- dry conditions

Fact 1: The Earth revolving around the Sun causes the seasons to change on its axis. Fact 2: Seasons are caused because the earth's axis is tilted as the earth revolves around the sun. Given the two facts above, what causes seasons?
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A: earth's revolving

Problem:OPTIONS:
- grave error
- an object
- a gravity drain
- mass grave
- deoxyribonucleic acid
- Physical weathering
- gravity depletion
- hydrogen and oxygen

Fact 1: Ablack hole is formed by a high-mass star collapses. Fact 2: Essentially, a black hole is a gravity drain. Given the two facts above, what is formed by a high-mass star collapses?
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A: a gravity drain

Problem:OPTIONS:
- the Great Barrier Reef
- Nurseries of the ocean.
- over the mountains
- over the valleys
- summer end
- over the plains
- swamp vegetation
- over the deserts

Fact 1: Sunlight and rain can cause a rainbow. Fact 2: All deserts have very little rain. Given the two facts above, where do rainbows rarely appear?
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A: over the deserts

Problem:OPTIONS:
- coastlines
- San Francisco
- mouth of rivers
- germany
- Movement
- a hydraulic system
- permineralization
- near the shoreline

Fact 1: Tectonic plates being pushed together causes earthquakes. Fact 2: For example, an earthquake hits San Francisco. Given the two facts above, where might you find tectonic plates being pushed together?
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A:
San Francisco