input: OPTIONS:
- garbage
- Generating heat
- Space travel
- running and lifting
- Time and energy
- exercise
- money
- Riding a bike Now, answer this question: Fact 1: Playing is one way mammals and other animals learn how to behave. Fact 2: Involvement in play takes time and energy. Given the two facts above, what is one way animals learn to behave?
A:
output: Time and energy

input: OPTIONS:
- empty spaces
- big spaces
- building blocks
- small parts
- solid, liquid, gas
- Organic compounds
- layers of fat
- bioaerosols Now, answer this question: Fact 1: Lipids may consist of fatty acids alone, or they may contain other molecules as well. Fact 2: Fatty acids are the building blocks of lipids. Given the two facts above, what of lipids may contain other molecules as well?
A:
output: building blocks

input: OPTIONS:
- Pollution
- reproduction
- viruses
- disease
- habitat
- ecosystems
- influenza
- deforestation Now, answer this question: Fact 1: Harming an animal species has a negative impact on the population size of that species. Fact 2: Pollution is usually harmful to one or more species of animal or plant. Given the two facts above, what is usually harmful to the population size of a species?
A:
output:
Pollution