Fact 1: Air pollution harms the respiratory and circulatory systems. Fact 2: Smoking is a form of air pollution. Given the two facts above, what harms the respiratory and circulatory systems?

OPTIONS:
- Cars
- oxygen
- smoking
- vehicles
- emissions
- gasoline
- fresh air
- lungs

Answer: smoking

Fact 1: Decomposition increases the amount of nutrients in the soil. Fact 2: Bacteria and fungi are involved in the decomposition. Given the two facts above, what can increase the amount of nutrients in the soil?

OPTIONS:
- roots
- wind
- worms
- Fungi
- Enzymes
- corn
- trees
- mussels

Answer: Fungi

Fact 1: Most arthropods are insects. Fact 2: Scorpions are very distinctive arthropods. Given the two facts above, what are scorpions?

OPTIONS:
- strong
- infected
- insects
- animals
- fertile
- Catch prey
- long tail
- dangerous

Answer: insects

Fact 1: Biofuel is used to produce electricity by burning. Fact 2: Wood and straw are both examples of biofuels. Given the two facts above, what is used to produce electricity by burning?

OPTIONS:
- carbon
- Oak
- light
- coal
- fish
- food
- wood
- oil

Answer:
wood