Input: American Idol
This was the first season where the contestants were permitted to perform in the final rounds songs they wrote themselves. In the Top 8, Sam Woolf received the fewest votes, but he was saved from elimination by the judges. The 500th episode of the series was the Top 3 performance night.

Contestants could perform what in the final rounds for the first time ever?
Output: songs they wrote themselves

Input: Zinc
Brass, which is an alloy of copper and zinc, has been used since at least the 10th century BC in Judea and by the 7th century BC in Ancient Greece. Zinc metal was not produced on a large scale until the 12th century in India and was unknown to Europe until the end of the 16th century. The mines of Rajasthan have given definite evidence of zinc production going back to the 6th century BC. To date, the oldest evidence of pure zinc comes from Zawar, in Rajasthan, as early as the 9th century AD when a distillation process was employed to make pure zinc. Alchemists burned zinc in air to form what they called "philosopher's wool" or "white snow".

What early process was used to make zinc?
Output: distillation process

Input: Nigeria
Waste management including sewage treatment, the linked processes of deforestation and soil degradation, and climate change or global warming are the major environmental problems in Nigeria. Waste management presents problems in a mega city like Lagos and other major Nigerian cities which are linked with economic development, population growth and the inability of municipal councils to manage the resulting rise in industrial and domestic waste. This huge waste management problem is also attributable to unsustainable environmental management lifestyles of Kubwa Community in the Federal Capital Territory, where there are habits of indiscriminate disposal of waste, dumping of waste along or into the canals, sewerage systems that are channels for water flows, etc.

What is the largest Nigerian city?
Output: Lagos

Input: London
The London Fire Brigade is the statutory fire and rescue service for Greater London. It is run by the London Fire and Emergency Planning Authority and is the third largest fire service in the world. National Health Service ambulance services are provided by the London Ambulance Service (LAS) NHS Trust, the largest free-at-the-point-of-use emergency ambulance service in the world. The London Air Ambulance charity operates in conjunction with the LAS where required. Her Majesty's Coastguard and the Royal National Lifeboat Institution operate on the River Thames, which is under the jurisdiction of the Port of London Authority from Teddington Lock to the sea.

What agency provides fire fighting and rescue service in London?
Output:
The London Fire Brigade