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: So, my 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. The answer is (C).

Q: What is the euphrates larger than?
Options:
- (A) ocean
- (B) planet
- (C) trees
- (D) sea
- (E) Inches
- (F) Sediment
- (G) stream
- (H) Length
A: So, my chain of thought: Rivers are usually larger than streams. And the fourth river is the Great River, the river Euphrates. The Euphrates is larger than a stream. The answer is (G).

Q: What do muscle fibers need to do to enable movement?
Options:
- (A) Bend
- (B) strength
- (C) exercise
- (D) ligt
- (E) It expands
- (F) shorten
- (G) Vibrates
- (H) stay warm
A:
So, my chain of thought: Muscle contraction occurs when muscle fibers get shorter. Movement is based on the contraction of muscles. Movement happens when muscle fibers get shorter. The answer is (F).