Problem:OPTIONS:
- parasites
- resistance
- part of
- native
- attached
- Allergies
- foreign
- humans

Fact 1: Antigens are molecules that the immune system recognizes as foreign to the body. Fact 2: Antibodies respond to antigens by latching on to, or binding with, the antigens. Given the two facts above, antibodies responds to molecules that the immune system recognizes as what to the body?
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A: foreign

Problem:OPTIONS:
- particle explosion
- friction
- silence
- ice forming
- heat energy
- Energy.
- energy
- resonance

Fact 1: Hitting an object causes the particles in that object to vibrate. Fact 2: Geoffrey stops to hit a gong in different places, testing the concept of resonance. Given the two facts above, what does gong's particles vibrating cause?
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A: resonance

Problem:OPTIONS:
- fur seals
- insects
- animals
- bacteria
- Most plants
- ferns
- humans
- barnacles

Fact 1: Cytokinesis is the final stage of cell division in eukaryotes as well as prokaryotes. Fact 2: Prokaryotes All bacteria are prokaryotes. Given the two facts above, cytokenisis is the final stage of cell division in what?
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A: bacteria

Problem:OPTIONS:
- fossil fuels
- light pollution
- Pollution
- drought
- rainbow falls
- Greenhouse gasses
- lunar eclipse
- air pollution

Fact 1: Air pollution can cause the pH of soil to decrease. Fact 2: Highly acid soil is detrimental to crop growth and biological activity in soil. Given the two facts above, crop growth can be negatively impacted by?
****
A:
air pollution