Which object would be the best addition to a collection of writing instruments that are unique to the twentieth century? a) a pencil b) a computer c) a crayon d) a calligraphy pen

B) a computer. The advent of technology in all aspect of human life made life simple and easy.The fast processing and error checks makes writing in computer a unique to 20th century. The handwriting never significant here as one can take any font to inscribe the text and the standardization and uniqueness of each characters makes computer typing the best of all writing tools. The features available are enormous that one has different options available in writing in computers.

Generally spontaneous human combustion is something that still bewilders some, human combustion happens very rarely and doesn't affect the surrounding areas, so unless you want to set your self on fire, human combustion will remain spontaneous and very rare.