Input: Nigeria
For centuries, various peoples in modern-day Nigeria traded overland with traders from North Africa. Cities in the area became regional centres in a broad network of trade routes that spanned western, central and northern Africa. In the 16th century, Spanish and Portuguese explorers were the first Europeans to begin significant, direct trade with peoples of modern-day Nigeria, at the port they named Lagos and in Calabar. Europeans traded goods with peoples at the coast; coastal trade with Europeans also marked the beginnings of the Atlantic slave trade. The port of Calabar on the historical Bight of Biafra (now commonly referred to as the Bight of Bonny) become one of the largest slave trading posts in West Africa in the era of the transatlantic slave trade. Other major slaving ports in Nigeria were located in Badagry, Lagos on the Bight of Benin and on Bonny Island on the Bight of Biafra. The majority of those enslaved and taken to these ports were captured in raids and wars. Usually the captives were taken back to the conquerors' territory as forced labour; after time, they were sometimes acculturated and absorbed into the conquerors' society. A number of slave routes were established throughout Nigeria linking the hinterland areas with the major coastal ports. Some of the more prolific slave traders were linked with the Oyo Empire in the southwest, the Aro Confederacy in the southeast and the Sokoto Caliphate in the north.

What is the current name of the Bight of Biafra?
Output: Bight of Bonny

Input: Classical music
The Classical era, from about 1750 to 1820, established many of the norms of composition, presentation, and style, and was also when the piano became the predominant keyboard instrument. The basic forces required for an orchestra became somewhat standardized (although they would grow as the potential of a wider array of instruments was developed in the following centuries). Chamber music grew to include ensembles with as many as 8 to 10 performers for serenades. Opera continued to develop, with regional styles in Italy, France, and German-speaking lands. The opera buffa, a form of comic opera, rose in popularity. The symphony came into its own as a musical form, and the concerto was developed as a vehicle for displays of virtuoso playing skill. Orchestras no longer required a harpsichord (which had been part of the traditional continuo in the Baroque style), and were often led by the lead violinist (now called the concertmaster).

What is an opera buffa?
Output: a form of comic opera

Input: Alexander Graham Bell
Bell began a series of public demonstrations and lectures to introduce the new invention to the scientific community as well as the general public. A short time later, his demonstration of an early telephone prototype at the 1876 Centennial Exposition in Philadelphia brought the telephone to international attention. Influential visitors to the exhibition included Emperor Pedro II of Brazil. Later Bell had the opportunity to demonstrate the invention personally to Sir William Thomson (later, Lord Kelvin), a renowned Scottish scientist, as well as to Queen Victoria, who had requested a private audience at Osborne House, her Isle of Wight home. She called the demonstration "most extraordinary". The enthusiasm surrounding Bell's public displays laid the groundwork for universal acceptance of the revolutionary device.

What important person saw the telephone at the Centennial Exposition?
Output: Emperor Pedro II

Input: Muammar Gaddafi
With crude oil as the country's primary export, Gaddafi sought to improve Libya's oil sector. In October 1969, he proclaimed the current trade terms unfair, benefiting foreign corporations more than the Libyan state, and by threatening to reduce production, in December Jalloud successfully increased the price of Libyan oil. In 1970, other OPEC states followed suit, leading to a global increase in the price of crude oil. The RCC followed with the Tripoli Agreement, in which they secured income tax, back-payments and better pricing from the oil corporations; these measures brought Libya an estimated $1 billion in additional revenues in its first year.

How much money did Libya accrue in a year as a result of the Tripoli Agreement?
Output:
$1 billion