Input: Buckingham Palace
At the centre of this wing is the famous balcony with the Centre Room behind its glass doors. This is a Chinese-style saloon enhanced by Queen Mary, who, working with the designer Sir Charles Allom, created a more "binding" Chinese theme in the late 1920s, although the lacquer doors were brought from Brighton in 1873. Running the length of the piano nobile of the east wing is the great gallery, modestly known as the Principal Corridor, which runs the length of the eastern side of the quadrangle. It has mirrored doors, and mirrored cross walls reflecting porcelain pagodas and other oriental furniture from Brighton. The Chinese Luncheon Room and Yellow Drawing Room are situated at each end of this gallery, with the Centre Room obviously placed in the centre.

The Principle Corridor features which type of doors?
Output: mirrored doors

Input: Article: The largest mammal to live in the highest altitudes are the alpine ibex, which have been sighted as high as 3,000 m (9,843 ft). The ibex live in caves and descend to eat the succulent alpine grasses. Classified as antelopes, chamois are smaller than ibex and found throughout the Alps, living above the tree line and are common in the entire alpine range. Areas of the eastern Alps are still home to brown bears. In Switzerland the canton of Bern was named for the bears but the last bear is recorded as having been killed in 1792 above Kleine Scheidegg by three hunters from Grindelwald.

Now answer this question: How high have the Alpine Ibex been sighted?

Output: as high as 3,000 m (9,843 ft)

Article: Eritrea is a multilingual country. The nation has no official language, as the Constitution establishes the "equality of all Eritrean languages". However, Tigrinya serves as the de facto language of national identity. With 2,540,000 total speakers of a population of 5,254,000 in 2006, Tigrinya is the most widely spoken language, particularly in the southern and central parts of Eritrea. Modern Standard Arabic and English serve as de facto working languages, with the latter used in university education and many technical fields. Italian, the former colonial language, is widely used in commerce and is taught as a second language in schools, with a few elderly monolinguals.

Question: What languages serve as de facto working languages in Eritrea?
Ans: Modern Standard Arabic and English

Here is a question about this article: In the year 712, Muhammad bin Qasim, an Umayyad general, sailed from the Persian Gulf into Sindh in Pakistan and conquered both the Sindh and the Punjab regions along the Indus river. The conquest of Sindh and Punjab, in modern-day Pakistan, although costly, were major gains for the Umayyad Caliphate. However, further gains were halted by Hindu kingdoms in India in the battle of Rajasthan. The Arabs tried to invade India but they were defeated by the north Indian king Nagabhata of the Pratihara Dynasty and by the south Indian Emperor Vikramaditya II of the Chalukya dynasty in the early 8th century. After this the Arab chroniclers admit that the Caliph Mahdi "gave up the project of conquering any part of India."
What is the answer to this question: At what battle did the Hindus of India defeat the Umayyads?
****
So... Rajasthan

The problem: Answer a question about this article:
Stage lifts and orchestra lifts are specialized elevators, typically powered by hydraulics, that are used to raise and lower entire sections of a theater stage. For example, Radio City Music Hall has four such elevators: an orchestra lift that covers a large area of the stage, and three smaller lifts near the rear of the stage. In this case, the orchestra lift is powerful enough to raise an entire orchestra, or an entire cast of performers (including live elephants) up to stage level from below. There's a barrel on the background of the image of the left which can be used as a scale to represent the size of the mechanism
How are stage lifts powered?
****
The answer: by hydraulics

The problem: Answer a question about this article:
This makes for a large number of takeoffs and landings and it is not unusual for flights to be delayed in the holding pattern before landing. Following the airport's master plan, Infraero built a second runway, which was finished in 2006. In 2007, the airport handled 11,119,872 passengers. The main building's third floor, with 12 thousand square meters, has a panoramic deck, a food court, shops, four movie theatres with total capacity of 500 people, and space for exhibitions. Brasilia Airport has 136 vendor spaces. The airport is located about 11 km (6.8 mi) from the central area of Brasilia, outside the metro system. The area outside the airport's main gate is lined with taxis as well as several bus line services which connect the airport to Brasilia's central district. The parking lot accommodates 1,200 cars. The airport is serviced by domestic and regional airlines (TAM, GOL, Azul, WebJET, Trip and Avianca), in addition to a number of international carriers. In 2012, Brasilia's International Airport was won by the InfrAmerica consortium, formed by the Brazilian engineering company ENGEVIX and the Argentine Corporacion America holding company, with a 50% stake each. During the 25-year concession, the airport may be expanded to up to 40 million passengers a year.
How many passengers came through Brasilia's airport in 2007?
****
The answer:
11,119,872