This task is about writing a correct answer for the reading comprehension task. Based on the information provided in a given passage, you should identify the shortest continuous text span from the passage that serves as an answer to the given question. Avoid answers that are incorrect or provides incomplete justification for the question.

Input: Consider Input: Passage: Naturally occurring glass, especially the volcanic glass obsidian, has been used by many Stone Age societies across the globe for the production of sharp cutting tools and, due to its limited source areas, was extensively traded. But in general, archaeological evidence suggests that the first true glass was made in coastal north Syria, Mesopotamia or ancient Egypt. The earliest known glass objects, of the mid third millennium BCE, were beads, perhaps initially created as accidental by-products of metal-working (slags) or during the production of faience, a pre-glass vitreous material made by a process similar to glazing. Question: What was obsidian used to make in prehistoric times?

Output: cutting tools


Input: Consider Input: Passage: Other cities with a concentration of secular Gothic include Bruges and Siena. Most surviving small secular buildings are relatively plain and straightforward; most windows are flat-topped with mullions, with pointed arches and vaulted ceilings often only found at a few focal points. The country-houses of the nobility were slow to abandon the appearance of being a castle, even in parts of Europe, like England, where defence had ceased to be a real concern. The living and working parts of many monastic buildings survive, for example at Mont Saint-Michel. Question: What style are most windows on secular Gothic structures?

Output: flat-topped with mullions


Input: Consider Input: Passage: The presence of the Virgin Mary under the cross[Jn. 19:26-27] has in itself been the subject of Marian art, and well known Catholic symbolism such as the Miraculous Medal and Pope John Paul II's Coat of Arms bearing a Marian Cross. And a number of Marian devotions also involve the presence of the Virgin Mary in Calvary, e.g., Pope John Paul II stated that "Mary was united to Jesus on the Cross". Well known works of Christian art by masters such as Raphael (e.g., the Mond Crucifixion), and Caravaggio (e.g., his Entombment) depict the Virgin Mary as part of the crucifixion scene. Question: Who painted the Mond Crucifixion.


Output: Raphael