Teacher: 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.
Teacher: Now, understand the problem? If you are still confused, see the following example:
Passage: The French and Indian War (17541763) was the North American theater of the worldwide Seven Years' War. The war was fought between the colonies of British America and New France, with both sides supported by military units from their parent countries of Great Britain and France, as well as Native American allies. At the start of the war, the French North American colonies had a population of roughly 60,000 European settlers, compared with 2 million in the British North American colonies. The outnumbered French particularly depended on the Indians. Long in conflict, the metropole nations declared war on each other in 1756, escalating the war from a regional affair into an intercontinental conflict. Question: When was the French and Indian War?
Solution: 1754-1763
Reason: It is a common convention to write (start year-end year) beside a historical event to understand when the event happened. We can observe a similar notation from the passage to conclude that the French and Indian War happened during 17541763. Therefore, the answer is 17541763.

Now, solve this instance: Passage: The tourism industry began in the early 19th century when foreigners visited the Alps, traveled to the bases of the mountains to enjoy the scenery, and stayed at the spa-resorts. Large hotels were built during the Belle Epoque; cog-railways, built early in the 20th century, brought tourists to ever higher elevations, with the Jungfraubahn terminating at the Jungfraujoch, well above the eternal snow-line, after going through a tunnel in Eiger. During this period winter sports were slowly introduced: in 1882 the first figure skating championship was held in St. Moritz, and downhill skiing became a popular sport with English visitors early in the 20th century, as the first ski-lift was installed in 1908 above Grindelwald. Question: When were large hotels built in the Alps?
Student:
during the Belle Epoque