Problem:OPTIONS:
- backbone
- tissue
- alveoli
- life
- heat energy
- a cuticle
- food
- shell

Fact 1: Mollusks are invertebrates such as the common snail. Fact 2: Invertebrates have no backbone. Given the two facts above, what do mollusks not have?
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A: backbone

Problem:OPTIONS:
- members of their own species
- raindrops
- female gametophytes
- Chlorophyll
- major threat to health
- stems
- leaves
- it keeps an organism warm

Fact 1: Female gametophytes produce eggs inside the ovaries of flowers. Fact 2: Microspores develop into female gametophyte that produces egg in archegonium. Given the two facts above, what do microspores develop into?
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A: female gametophytes

Problem:OPTIONS:
- interpretive dance
- semiochemicals
- insects
- smoke signals
- sensory neurons
- Electrical energy
- sunlight
- Chemical energy

Fact 1: Ants communicate with chemicals called pheromones. Fact 2: Pheromones are a sub-category of semiochemicals. Given the two facts above, what do ants communicate with?
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A: semiochemicals

Problem:OPTIONS:
- water
- parasitic
- epidermis and dermis
- the immune response
- Veins and arteries.
- Most plants
- the body's largest organ
- Trojan worm

Fact 1: HIV infects and destroys helper T cells. Fact 2: Helper T Cells Helper T cells are the brains behind immune response. Given the two facts above, what can HIV infect and destroy part of?
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A:
the immune response