Student A:Passage: In North America, trick-or-treating has been a Halloween tradition since the late 1920s. In Britain and Ireland the tradition of going house-to-house collecting food at Halloween goes back at least as far as the 16th century, as had the tradition of people wearing costumes at Halloween. In 19th century Britain and Ireland, there are many accounts of people going house-to-house in costume at Halloween, reciting verses in exchange for food, and sometimes warning of misfortune if they were not welcomed. The Scottish Halloween custom of "guising" -- children disguised in costume going from house to house for food or money -- is first recorded in North America in 1911 in Ontario, Canada. While going house-to-house in costume has remained popular among Scots and Irish, the custom of saying "trick or treat" has only recently become common. The activity is prevalent in the United States, Canada, the United Kingdom, the Republic of Ireland, Puerto Rico, and northwestern and central Mexico. In the latter, this practice is called calaverita (Spanish for "sugar skull"), and instead of "trick or treat", the children ask me da mi calaverita? ("can you give me my sugar skull?") where a calaverita is a small skull made of sugar or chocolate.

Question: Based on this passage, when did trick or treating begin in america?
Student B:OK... To answer the above question, the relevant sentence is: In North America, trick-or-treating has been a Halloween tradition since the late 1920s.
the late 1920s.

Student A:Celebrity Big Brother, also known as Big Brother: Celebrity Edition, is a spin-off series of the American reality television series Big Brother. This season aired during the winter of the 2017 -- 18 network television season on CBS and was the second U.S. Big Brother season to air outside the usual summer television season, the first being Big Brother 9 in 2008. Julie Chen returned as host, with Allison Grodner and Rich Meehan returning as executive producers. The season was produced by Fly on the Wall Entertainment in association with Endemol Shine North America. The season premiered on February 7, 2018.

Answer this question based on the passage: when does big brother celebrity edition start 2018?
Student B:OK... To answer the above question, the relevant sentence is: The season premiered on February 7, 2018.
February 7 , 2018.

Student A:Kefir or kephir (/ kfr / k-FEER), alternatively milk kefir or bulgaros, is a fermented milk drink that originated in the Caucasus Mountains made with kefir "grains", a yeast / bacterial fermentation starter. It is prepared by inoculating cow, goat, or sheep milk with kefir grains. Traditional kefir was made in goatskin bags that were hung near a doorway; the bag would be knocked by anyone passing through to help keep the milk and kefir grains well mixed.

Answer this question: where did the first kefir grains come from?
Student B:OK... The relevant information is: Kefir or kephir (/ kfr / k-FEER), alternatively milk kefir or bulgaros, is a fermented milk drink that originated in the Caucasus Mountains made with kefir "grains", a yeast / bacterial fermentation starter.
the Caucasus Mountains.

Student A:Context: Springfield's original name was Calhoun, after Senator John C. Calhoun of South Carolina. The land that Springfield now occupies was originally settled by trappers and traders who came to the Sangamon River in 1818. The settlement's first cabin was built in 1820, by John Kelly. It was located at what is now the northwest corner of Second Street and Jefferson Street. In 1821, Calhoun became the county seat of Sangamon County due to fertile soil and trading opportunities. Settlers from Kentucky, Virginia, and as far as North Carolina came to the city. By 1832, Senator Calhoun had fallen out of the favor with the public and the town renamed itself Springfield after Springfield, Massachusetts. At that time, Springfield, Massachusetts was comparable to modern-day Silicon Valley -- known for industrial innovation, concentrated prosperity, and the celebrated Springfield Armory. Most importantly, it was a city that had built itself up from frontier outpost to national power through ingenuity -- an example that the newly named Springfield, Illinois, sought to emulate. Kaskaskia was the first capital of the Illinois Territory from its organization in 1809, continuing through statehood in 1818, and through the first year as a state in 1819. Vandalia was the second state capital of Illinois from 1819 to 1839. Springfield became the third and current capital of Illinois in 1839. The designation was largely due to the efforts of Abraham Lincoln and his associates; nicknamed the "Long Nine" for their combined height of 54 feet (16 m).

Question: when did springfield become the capital of illinois?
Student B:
OK... To answer this question, we should know that: Springfield became the third and current capital of Illinois in 1839.
1839.