Read the excerpt from "How the Grimm Brothers Saved the Fairy Tale." When Jacob (b. 1785) and Wilhelm (b. 1786) began collecting folk tales and songs at the beginning of the nineteenth century, they were precocious students at the University of Marburg, still in their teens . They grew up quite fast, plagued by money problems and caring for their siblings—their father died in 1796, leaving the once middle-class family in poverty. Their situation was further aggravated by the rampant Napoleonic Wars. Jacob interrupted his studies to serve the Hessian War Commission, although Wilhelm passed his law exams and found work as a low-paid librarian in the royal library. In 1807, Jacob lost his position with the War Commission, when the French occupied Kassel, but he was then hired as a librarian for the new King Jérome, Napoleon’s brother, who now ruled Westphalia. Amidst all the upheavals, their mother died in 1808, and Jacob and Wilhelm became fully responsible for their three younger brothers and sister. Which structure is used in this excerpt?