Fact 1: Cell division often causes growth. Fact 2: Cell division is relatively slow and requires a lot of energy. Given the two facts above, answer the question "What often requires a lot of energy?" with the following options: - pigeons - monkeys - horizon - growth - humans - omnivores - waiting - distance
growth

Fact 1: Biofuel is used to produce electricity by burning. Fact 2: Biofuels include ethanol, methanol, biodiesel, biocrude, and methane. Given the two facts above, answer the question "If ethanol were burned, what could be made?" with the following options: - nuclear waste - energy - massive damage - coal tar - Solutions - engines - electricity - plastic
electricity

Q: Fact 1: Muscle contraction occurs when muscle fibers get shorter. Fact 2: Muscles are bundles of fibers that can contract. Given the two facts above, answer the question "What contracts as it gets shorter?" with the following options: - layers of fat - Epidermis - Veins and arteries. - Shortstop - Labor - Contracts - the body's largest organ - Bundles of fibers
A: Bundles of fibers

Question: Fact 1: Abreathing mask is used for keeping harmful particles from entering the respiratory system. Fact 2: When mold grows in the house, it can emit particles that travel through the air. Given the two facts above, answer the question "What can keep mold from entering the respiratory system?" with the following options: - vaccinations - layers of fat - deep breaths - sweating - a breathing mask - moisture - organic molecules - hydrogen and oxygen
Answer: a breathing mask

*Question*
Fact 1: Veins generally carry deoxygenated blood. Fact 2: Deoxygenated blood is heavy with carbon dioxide. Given the two facts above, answer the question "What does blood in the veins have a lot of?" with the following options: - Carbon dioxide - Carbon monoxide - h2o - Energy. - Air - kinetic energy - Decibels - Chemical energy
**Answer**
Carbon dioxide

Fact 1: Bacteria in soil convert atmospheric nitrogen into a form usable by plants. Fact 2: Bacteria are single-celled organisms. Given the two facts above, answer the question "What in soil converts atmospheric nitrogen into a form usable by plants?" with the following options: - compound of hydrogen oxygen - carbohydrates - single-celled organisms - excretory structures - peachleaf willow - members of their own species - It helps them survive - deoxyribonucleic acid
single-celled organisms