Fact 1: The number of rings in a tree trunk can be used to estimate the age of the tree. Fact 2: Age of Pine trees (AGE) in years. Given the two facts above, what unit of time can be estimated by the rings in a tree trunk?

OPTIONS:
- hours
- decades
- months
- H20
- Joules
- DNA
- years
- seasons

Answer: years

Fact 1: All chemical reactions require activation energy to get started. Fact 2: Chemical changes are a result of chemical reactions. Given the two facts above, what is required before a chemical change?

OPTIONS:
- kinetic energy
- energy usage
- activation push
- activation energy
- activation switch
- activation power
- Burning fuel and air
- Evaporation

Answer: activation energy

Fact 1: Earthworms are important deposit feeders that help form and enrich soil. Fact 2: Earthworms are terrific for plants and soil. Given the two facts above, what are earthworms important for?

OPTIONS:
- survival
- recovery
- food
- fields
- Earth
- plants
- animals
- potatoes

Answer: plants

Fact 1: Echinoderms use pheromones to communicate with each other. Fact 2: Echinoderms are represented by the starfish. Given the two facts above, starfish use _ to communicate with each other.?

OPTIONS:
- scattered light
- pheromones
- heat produced
- sound
- waves
- Chemical energy
- electricity
- kinetic energy

Answer:
pheromones