Meteor showers and individual streaks of light that flash across the sky every night are generated when tiny flecks of celestial detritus, often no larger than grains of sand or of pebbles, burn up speeding through the atmosphere.
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Agrains of sand or of pebbles, burn up speeding
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Bgrains of sand or pebbles, burn up while speeding
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Cgrains of sand or pebbles, which burn up while speeding
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Da grain of sand or pebble, which burns up as it speeds
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Ea grain of sand or a pebble, burns up when it speeds
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