You are given a background paragraph that describes one or more causal or physical relationships, such as a relationship in economics, scientific law, or nature. You need to come up with a fictional story that makes use of the concepts or the relationship described in the provided paragraph. Make sure that your story does not repeat the relation in the given paragraph (e.g., by avoiding verbatim copies of the given paragraph). Start by reading the background paragraph, and determine what relationship(s) are in the paragraph. Write a story that involves the relationship(s) that you determined are in the background paragraph. Try to use your own words as much as possible and not repeat the background paragraph. Feel free to make up places and events as long as they tie back to the background paragraph in a way that you can ask a question about.

[Q]: Background Paragraph: Nearsightedness, or myopia, is the condition in which nearby objects are seen clearly, but distant objects appear blurry. The Figure below shows how it occurs. The eyeball is longer (from front to back) than normal. This causes images to be focused in front of the retina instead of on the retina. Myopia can be corrected with concave lenses. The lenses focus images farther back in the eye, so they fall on the retina instead of in front of it.
[A]: John and Keith are two friends. They went to see an ophthalmologist for an eye cheek up. The doctor found that John had myopia, but Keith had normal eyes. He advised them according to his findings.

[Q]: Background Paragraph: The epidermis also contains melanocytes , which are cells that produce melanin. Melanin is the brownish pigment that gives skin much of its color. Everyone has about the same number of melanocytes, but the melanocytes of people with darker skin produce more melanin. The amount of melanin produced is determined by heredity and exposure to UV light, which increases melanin output. Exposure to UV light also stimulates the skin to produce vitamin D . Because melanin blocks UV light from penetrating the skin, people with darker skin may be at greater risk of vitamin D deficiency.
[A]: An anthropologist gathered observations for two native tribes from southern Africa. He noticed that both tribes spend the majority of the day outside, and therefore they are both exposed to fairly high amounts of UV light. He also quickly realized that one key difference between the tribes was that members of tribe A had dark skin, while members of tribe B had light skin.

[Q]: Background Paragraph: Through a thickness of 10 meters (33 ft) or more, however, the intrinsic color of water (or ice) is visibly turquoise (greenish blue), as its absorption spectrum has a sharp minimum at the corresponding color of light (1/227 m1 at 418 nm). The color becomes increasingly stronger and darker with increasing thickness. (Practically no sunlight reaches the parts of the oceans below 1,000 meters (3,300 ft) of depth.) Infrared and ultraviolet light, on the other hand, is strongly absorbed by water.
[A]:
David was interested in the coloration of ocean's water. To understand the phenomenon he first observed the color of water at forty feet depth. He noted his observation as point A. Then he observed the color at hundred feet depth. He noted his observation as point B. Then he observed the color at four thousand feet depth. He noted that observation as point C. He now have some ideas how the color of water changes according to its depth.