In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

[EX Q]: The expansion of what further cemented Houston's emergence as a powerhouse commercial city?, Context: By 1860, Houston had emerged as a commercial and railroad hub for the export of cotton. Railroad spurs from the Texas inland converged in Houston, where they met rail lines to the ports of Galveston and Beaumont. During the American Civil War, Houston served as a headquarters for General John Bankhead Magruder, who used the city as an organization point for the Battle of Galveston. After the Civil War, Houston businessmen initiated efforts to widen the city's extensive system of bayous so the city could accept more commerce between downtown and the nearby port of Galveston. By 1890, Houston was the railroad center of Texas.
[EX A]: bayous

[EX Q]: What is Estonian War of independence?, Context: After the Estonian War of Independence in 1919, the Estonian language became the state language of the newly independent country. In 1945, 97.3% of Estonia considered itself ethnic Estonian and spoke the language.
[EX A]: War

[EX Q]: Athleticism can be demonstrated by Somalians in what way?, Context: All of these traditions, including festivals, martial arts, dress, literature, sport and games such as Shax, have immensely contributed to the enrichment of Somali heritage.
[EX A]:
sport and games