Problem:OPTIONS:
- Pesticides
- wind
- heat energy
- acid rain
- friction
- Pollution
- coal
- oil

Fact 1: Gases from burning coal and oil dissolving in water in the atmosphere causes acid rain. Fact 2: Coal-fired power plants contribute to acid rain. Given the two facts above, what can power plants cause?
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A: acid rain

Problem:OPTIONS:
- exoskeleton
- a cuticle
- barrel-shaped
- fibrous
- Collagen
- nutrients
- cellulose
- watershred

Fact 1: Waxy leaves are used for storing water by some plants. Fact 2: Leaves are covered with a waxy layer, the cuticle , which prevents water loss. Given the two facts above, leaves are covered with what, which is used to store water in plants?
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A: a cuticle

Problem:OPTIONS:
- animals
- adaptation
- unnatural selection
- Plants growth
- evolution stopping
- supernatural spirits
- rapid expansion
- competition

Fact 1: Evolution occurs by a process called natural selection. Fact 2: Adaptation is the result of natural selection. Given the two facts above, evolution occurs by a process that results in what?
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A: adaptation

Problem:OPTIONS:
- Most plants
- organs
- Plant reproduction
- ova and spermatozoa
- remains of prehistoric life
- hydrogen
- mitosis
- allow growth

Fact 1: Meiosis is the type of cell division that produces gametes. Fact 2: Examples of gametes are ova and spermatozoa. Given the two facts above, meiosis is the type of cell division that produces what?
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A:
ova and spermatozoa