Chain-of-thought: Brain cells die quickly if their oxygen supply is cut off. If the oxygen supply to the brain is cut off, a stroke can occur. Brain cells die quickly if a stroke occurs.
Q: What die quickly if a stroke occurs?
Options:
- (A) a fish
- (B) animals
- (C) brain cells
- (D) organs
- (E) critical organs
- (F) protons
- (G) neutrons
- (H) bones
A: (C)
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Chain-of-thought: Chromosomes contain genes, which code for proteins. Another gene, named BRCA2, has also been identified. Chromosomes contain BRCA2.
Q: Where is brca2 located?
Options:
- (A) retina
- (B) lungs
- (C) chromatic
- (D) the eyes
- (E) chromosome
- (F) chromography
- (G) chrome
- (H) sensory neurons
A: (E)
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Chain-of-thought: Most invertebrates have a nervous system. Insects are the most common invertebrates. Insects have a nervous system.

Q: What has a nervous system?
Options:
- (A) animals
- (B) tortoises
- (C) crocodiles
- (D) sponges
- (E) elephants
- (F) placozoans
- (G) mesozoans
- (H) insects
A: (H)
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