input: OPTIONS:
- energy
- heat
- Covering it with dirt
- sun's heat
- Removing fuel
- power
- fanning
- Dousing it with water Now, answer this question: Fact 1: Fanning a fire increases the oxygen near the fire. Fact 2: Fire needs oxygen to continue burning. Given the two facts above, what keeps a fire burning?
A:
output: fanning

Fact 1: Energy is used for heating a building by a heating system. Fact 2: Solar energy is the energy in the sun's rays. Given the two facts above, what can be used for heating a building by a heating system?

OPTIONS:
- the Sun's rays
- peachleaf willow
- engines
- oxygen
- photosynthesis
- photons
- air
- hydrogen and oxygen

Answer: the Sun's rays

Problem: OPTIONS:
- Exfoliation
- amble
- bite animals
- produce light
- grass
- reproduce
- sweating
- respirate
Q: Fact 1: Plants release oxygen during the day but not during the night. Fact 2: Oxygen exchange is needed for plant respiration. Given the two facts above, what do plants do during the day?
Answer: respirate

Problem:OPTIONS:
- seasons
- carbon dioxide
- flow of electrons
- gravitational pull
- fissures of hot, acidic water
- spinning on its axis
- heat energy
- energy of moving objects

Fact 1: Aplanet rotating causes cycles of day and night on that planet. Fact 2: Rotation simply means how long it takes a planet to spin on its axis. Given the two facts above, what causes day and night cycles on a planet?
****
A: spinning on its axis

Fact 1: Streams may start with runoff or water seeping out of a spring. Fact 2: Lakes and streams are sources of drinking water. Given the two facts above, what is a source of drinking water?
OPTIONS:
- ice expanding in rock openings
- helping to prevent floods
- industrial runoff
- it helps plants in growing
- Water seeping out of a spring
- salt water
- polluted water
- Something with a head, thorax, and abdomen
Water seeping out of a spring

Fact 1: The color of leaves on deciduous trees usually changes in the autumn season. Fact 2: Common deciduous trees are the oak, elm and beech. Given the two facts above, which tree's leaves change color in autumn?
OPTIONS:
- Fir
- wind
- Palm
- blue
- elms
- Oak
- Ficus
- Aves

Answer:
Oak