input: OPTIONS:
- By wind and rain
- Deposition
- Deposition.
- algae
- Chemical energy
- plant wall
- plant material
- polysaccharides Now, answer this question: Fact 1: Plants use cellulose for their cell walls. Fact 2: Another important polysaccharide is cellulose. Given the two facts above, what do plants build their cell walls from?
A:
output: polysaccharides

input: OPTIONS:
- smallpox
- A virus
- disease
- sun's heat
- cancer
- leukemia
- Pollution
- heat energy Now, answer this question: Fact 1: Skin is used for protecting the body from harmful substances. Fact 2: Pollution is the release of harmful substances into the environment. Given the two facts above, what does the skin protect against?
A:
output: Pollution

input: OPTIONS:
- Chemical dating
- Mechanical dating
- Non radioactive dating
- blastoids
- single-celled organisms
- Seismometer
- Radioactive dating
- an electron microscope Now, answer this question: Fact 1: Radioactive dating is used to determine the age of fossils. Fact 2: Geologists use fossils to determine the age of the rock layer that it was found in. Given the two facts above, what do geologists use to determine the age of rock layers?
A:
output:
Radioactive dating