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

Ex Input:
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 Output:
bayous


Ex Input:
Where is Cork, Context: The climate of Cork, like the rest of Ireland, is mild and changeable with abundant rainfall and a lack of temperature extremes. Cork lies in plant Hardiness zone 9b. Met Éireann maintains a climatological weather station at Cork Airport, a few kilometres south of the city. It should be noted that the airport is at an altitude of 151 metres (495 ft) and temperatures can often differ by a few degrees between the airport and the city itself. There are also smaller synoptic weather stations at UCC and Clover Hill.

Ex Output:
Ireland


Ex Input:
Whats needed to understand a group by it's presentation, Context: Quotient groups and subgroups together form a way of describing every group by its presentation: any group is the quotient of the free group over the generators of the group, quotiented by the subgroup of relations. The dihedral group D4, for example, can be generated by two elements r and f (for example, r = r1, the right rotation and f = fv the vertical (or any other) reflection), which means that every symmetry of the square is a finite composition of these two symmetries or their inverses. Together with the relations

Ex Output:

Quotient groups and subgroups