Input: Answer this question:
In a food pyramid, which best explains why the number of organisms decreases from one trophic level to the next?
OPTIONS:
- Consumers at the lower level require more energy than the top-level consumers.
- Consumers at the top level require more energy than the lower-level consumers.
- The consumers are feeding on larger organisms that have less energy.
- The consumers are feeding on smaller organisms that have less energy.
Answer: Consumers at the top level require more energy than the lower-level consumers.

*Question*: Which is a reason for Arkansas having multiple seasons? OPTIONS:
- the tilt of Earth's axis
- the speed of Earth's orbit
- Earth's distance from the Sun
- Earth gravitational pull toward the Moon
*Answer*: the tilt of Earth's axis

question:
As the human population increases, more fossil fuels are being used. The burning of fossil fuels produces greenhouse gases. How might humans reduce greenhouse gases?
OPTIONS:
- Buy cars that use gasoline.
- Build power plants that use coal.
- Use renewable resources to generate power.
- Use nonrenewable resources to generate power.

answer:
Use renewable resources to generate power.

[Q]: Which human organ system exchanges gases with the environment?
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OPTIONS:
- endocrine
- circulatory
- respiratory
- integumentary
****
[A]: respiratory

question below:
Iron oxides, such as rust, form when iron metal reacts with oxygen in the air. What are the chemical symbols for the two elements found in iron oxide?
OPTIONS:
- I and O
- Ir and O
- Fe and O
- Pb and O
answer below:
Fe and O

Input: Answer this question:
Which of the following is the major cause of tides?
OPTIONS:
- heating of the oceans by the Sun
- gravitational pull of the Moon
- earthquakes on the ocean floor
- changes in wind direction
Answer:
gravitational pull of the Moon