Problem:OPTIONS:
- make fire
- eat ice
- stay warm
- nothing
- fur
- motors
- shiver
- sweating

Fact 1: Mammals can also generate little bursts of heat by shivering. Fact 2: Polar bears are mammals. Given the two facts above, what can polar bears do to generate heat?
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A: shiver

Problem:OPTIONS:
- after too much water received
- movement of tectonic plates
- At the peak of a mountain
- a hemisphere is tilted away from the sun
- exposure to cold
- clouds
- soil
- the sun

Fact 1: An earthquake causes the ground to shake. Fact 2: Earthquakes are caused by movement of the tectonic plates. Given the two facts above, what makes the ground shake?
****
A: movement of tectonic plates

Problem:OPTIONS:
- damming a river
- power stations
- freezing h2o
- electricity
- burning fossil fuels
- hydrogen and oxygen
- sunlight
- nuclear meltdowns

Fact 1: Hydropower requires damming a river. Fact 2: Hydropower is a renewable, economical source of electricity. Given the two facts above, what does a renewable, economical source of electricity require?
****
A: damming a river

Problem:OPTIONS:
- water vapor
- nutrients
- ocean water
- Heat energy
- body water
- kinetic energy
- cold energy
- electric energy

Fact 1: Freezing means changing from a liquid into a solid by reducing heat energy. Fact 2: When ice freezes, it releases heat energy into the environment. Given the two facts above, what does ice lose when it is made?
****
A:
Heat energy