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:
What is the most expensive street in the country?, Context: The retail trade in Cork city includes a mix of both modern, state of the art shopping centres and family owned local shops. Department stores cater for all budgets, with expensive boutiques for one end of the market and high street stores also available. Shopping centres can be found in many of Cork's suburbs, including Blackpool, Ballincollig, Douglas, Ballyvolane, Wilton and Mahon Point. Others are available in the city centre. These include the recently[when?] completed development of two large malls The Cornmarket Centre on Cornmarket Street, and new the retail street called "Opera Lane" off St. Patrick's Street/Academy Street. The Grand Parade scheme, on the site of the former Capitol Cineplex, was planning-approved for 60,000 square feet (5,600 m2) of retail space, with work commencing in 2016. Cork's main shopping street is St. Patrick's Street and is the most expensive street in the country per sq. metre after Dublin's Grafton Street. As of 2015[update] this area has been impacted by the post-2008 downturn, with many retail spaces available for let.[citation needed] Other shopping areas in the city centre include Oliver Plunkett St. and Grand Parade. Cork is also home to some of the country's leading department stores with the foundations of shops such as Dunnes Stores and the former Roches Stores being laid in the city. Outside the city centre is Mahon Point Shopping Centre.

Ex Output:
Dublin's Grafton Street


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:
How do you know the core of a tree's trunk is likely still intact?, Context: It is remarkable that the inner heartwood of old trees remains as sound as it usually does, since in many cases it is hundreds, and in a few instances thousands, of years old. Every broken limb or root, or deep wound from fire, insects, or falling timber, may afford an entrance for decay, which, once started, may penetrate to all parts of the trunk. The larvae of many insects bore into the trees and their tunnels remain indefinitely as sources of weakness. Whatever advantages, however, that sapwood may have in this connection are due solely to its relative age and position.

Ex Output:

the inner heartwood of old trees remains as sound as it usually does