You will be given a definition of a task first, then an example. Follow the example to solve a new instance of the task.
In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

what is the first event mentioned?, Context: The Russian Revolution is the series of revolutions in Russia in 1917, which destroyed the Tsarist autocracy and led to the creation of the Soviet Union. Following the abdication of Nicholas II of Russia, the Russian Provisional Government was established. In October 1917, a red faction revolution occurred in which the Red Guard, armed groups of workers and deserting soldiers directed by the Bolshevik Party, seized control of Saint Petersburg (then known as Petrograd) and began an immediate armed takeover of cities and villages throughout the former Russian Empire.
Solution: Russian Revolution
Why? This is a good example, and the Russian Revolution is the first event mentioned.

New input: What did people first make mosaics from?, Context: Mosaic has a long history, starting in Mesopotamia in the 3rd millennium BC. Pebble mosaics were made in Tiryns in Mycenean Greece; mosaics with patterns and pictures became widespread in classical times, both in Ancient Greece and Ancient Rome. Early Christian basilicas from the 4th century onwards were decorated with wall and ceiling mosaics. Mosaic art flourished in the Byzantine Empire from the 6th to the 15th centuries; that tradition was adopted by the Norman kingdom in Sicily in the 12th century, by eastern-influenced Venice, and among the Rus in Ukraine. Mosaic fell out of fashion in the Renaissance, though artists like Raphael continued to practise the old technique. Roman and Byzantine influence led Jews to decorate 5th and 6th century synagogues in the Middle East with floor mosaics.
Solution:
Pebble