Input: Read this: The history of biodiversity during the Phanerozoic (the last 540 million years), starts with rapid growth during the Cambrian explosiona period during which nearly every phylum of multicellular organisms first appeared. Over the next 400 million years or so, invertebrate diversity showed little overall trend, and vertebrate diversity shows an overall exponential trend. This dramatic rise in diversity was marked by periodic, massive losses of diversity classified as mass extinction events. A significant loss occurred when rainforests collapsed in the carboniferous. The worst was the Permian-Triassic extinction event, 251 million years ago. Vertebrates took 30 million years to recover from this event.
Question: The Phanerozoic era covers what time period?

Output: the last 540 million years

Input: Read this: Athanasius's first problem lay with Meletius of Lycopolis and his followers, who had failed to abide by the First Council of Nicaea. That council also anathematized Arius. Accused of mistreating Arians and Meletians, Athanasius answered those charges at a gathering of bishops in Tyre, the First Synod of Tyre, in 335. There, Eusebius of Nicomedia and other supporters of Arius deposed Athanasius. On 6 November, both sides of the dispute met with Emperor Constantine I in Constantinople. At that meeting, the Arians claimed Athanasius would try to cut off essential Egyptian grain supplies to Constantinople. He was found guilty, and sent into exile to Augusta Treverorum in Gaul (now Trier in Germany).
Question: Constantinople was afraid they wouldn't receive grains from whom?

Output: unanswerable

Input: Read this: Many instruments today associated with popular music filled important roles in early classical music, such as bagpipes, vihuelas, hurdy-gurdies, and some woodwind instruments. On the other hand, instruments such as the acoustic guitar, once associated mainly with popular music, gained prominence in classical music in the 19th and 20th centuries.
Question: What instrument gained prominence in the 19th and 20th century?

Output: the acoustic guitar

Input: Read this: All major cities have their distinctive local department stores, which anchored the downtown shopping district until the arrival of the malls in the 1960s. Washington, for example, after 1887 had Woodward & Lothrop and Garfinckel's starting in 1905. Garfield's went bankrupt in 1990, as did Woodward & Lothrop in 1994. Baltimore had four major department stores: Hutzler's was the prestige leader, followed by Hecht's, Hochschild's and Stewart's. They all operated branches in the suburbs, but all closed in the late twentieth century. By 2015, most locally owned department stores around the country had been consolidated into larger chains, or had closed down entirely.
Question: When did Garfinckel's end operating in Washington?

Output:
unanswerable