Unusual Characteristics
In the 1970s Etna erupted smoke rings, one of the first captured events of this type, which are extremely rare. This happened again in 2000.
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Famous quotes containing the word unusual:
“Only in the most unusual cases is it useful to determine whether a book is good or bad; for it is just as rare for it to be one or the other. It is usually both.”
—Robert Musil (1880–1942)