The fourth movement of bartók's concerto for orchestra is in modified form. the form can be described as aba-interruption-ba. a. rondo b. sonata c. ternary d. minuet and trio

The fourth movement of Bartók's Concerto for Orchestra is in modified rondo form. Within rondo form, the main theme or refrain shifts with other contrasting themes, creating digressions or episodes. 

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.