Input: Read this: Punjab during Mahabharata times was known as Panchanada. Punjab was part of the Indus Valley Civilization, more than 4000 years ago. The main site in Punjab was the city of Harrapa. The Indus Valley Civilization spanned much of what is today Pakistan and eventually evolved into the Indo-Aryan civilisation. The Vedic civilisation flourished along the length of the Indus River. This civilisation shaped subsequent cultures in South Asia and Afghanistan. Although the archaeological site at Harappa was partially damaged in 1857 when engineers constructing the Lahore-Multan railroad used brick from the Harappa ruins for track ballast, an abundance of artefacts have nevertheless been found. Punjab was part of the great ancient empires including the Gandhara Mahajanapadas, Achaemenids, Macedonians, Mauryas, Kushans, Guptas, and Hindu Shahi. It also comprised the Gujar empire for a period of time, otherwise known as the Gurjara-Pratihara empire. Agriculture flourished and trading cities (such as Multan and Lahore) grew in wealth.
Question: When was the archaeological site at Harappa discovered?

Output: unanswerable

Input: Read this: Grazing organisms may also kill their prey species, but this is seldom the case. While some herbivores like zooplankton live on unicellular phytoplankton and therefore, by the individualized nature of the organism, kill their prey, many only eat a small part of the plant. Grazing livestock may pull some grass out at the roots, but most is simply grazed upon, allowing the plant to regrow once again. Kelp is frequently grazed in subtidal kelp forests, but regrows at the base of the blade continuously to cope with browsing pressure. Animals may also be 'grazed' upon; female mosquitos land on hosts briefly to gain sufficient proteins for the development of their offspring. Starfish may be grazed on, being capable of regenerating lost arms.
Question: How much of a starfish does phytoplnakton eat when it attaches to it?

Output: unanswerable

Input: Read this: London is a major international air transport hub with the busiest city airspace in the world. Eight airports use the word London in their name, but most traffic passes through six of these. London Heathrow Airport, in Hillingdon, West London, is the busiest airport in the world for international traffic, and is the major hub of the nation's flag carrier, British Airways. In March 2008 its fifth terminal was opened. There were plans for a third runway and a sixth terminal; however, these were cancelled by the Coalition Government on 12 May 2010.
Question: In terms of international travel, which airport is the world's busiest?

Output: London Heathrow

Input: Read this: Double deck elevators are used in the Taipei 101 office tower. Tenants of even-numbered floors first take an escalator (or an elevator from the parking garage) to the 2nd level, where they will enter the upper deck and arrive at their floors. The lower deck is turned off during low-volume hours, and the upper deck can act as a single-level elevator stopping at all adjacent floors. For example, the 85th floor restaurants can be accessed from the 60th floor sky-lobby. Restaurant customers must clear their reservations at the reception counter on the 2nd floor. A bank of express elevators stop only on the sky lobby levels (36 and 60, upper-deck car), where tenants can transfer to "local" elevators.
Question: During the low volume hours, what can the upper deck function as?

Output:
a single-level elevator stopping at all adjacent floors