One question per day; those who answer correctly receive 6 wealth points, while participants receive 2 wealth points； Question 263
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Fill-in-the-blank: Pure polyvinyl chloride exhibits a weak blue-green phosphorescent color under the illumination of ______ monochromatic light; under prolonged exposure to light, it undergoes ______, which changes its color to _______. Answer: Ultraviolet light ； aging ； Darker ；
Pure polyvinyl chloride exhibits a weak blue-green phosphorescent color under exposure to _ultraviolet_ monochromatic light; prolonged exposure to light causes _aging_, which results in a _darker_ color.
Pure polyvinyl chloride exhibits a weak blue-green phosphorescent color under exposure to _ultraviolet_ monochromatic light; prolonged exposure to light causes _aging_, which results in a _darker_ color.
Ultraviolet light. Aging. Darker. . . . .
Pure polyvinyl chloride exhibits a weak blue-green phosphorescent color under exposure to _ultraviolet___ monochromatic light; prolonged exposure to light causes __aging___, which results in a __darker___ color.
Pure polyvinyl chloride exhibits a weak blue-green phosphorescent color under exposure to monochromatic light from outside; it ages as a result of prolonged light exposure, causing its color to darken
Pure polyvinyl chloride exhibits a weak blue-green phosphorescent color under the exposure to ___ultraviolet___ monochromatic light; prolonged exposure to light causes _aging_____，which results in a ___darker___ color.
Answer: Ultraviolet rays, aging, darkening
Pure polyvinyl chloride exhibits a weak blue-green phosphorescent color under the illumination of ______ monochromatic light; under prolonged exposure to light, it undergoes ______, which changes its color to _______. Ultraviolet rays? Aging? Darkening
Pure polyvinyl chloride exhibits a weak blue-green phosphorescent color under the illumination of _ultraviolet_____ monochromatic light; prolonged exposure to light causes _aging_____ and results in a __darker_____ color.