instruction:
In this task, you're expected to write answers to questions involving multiple references to the same entity. The answer to the question should be unambiguous and a phrase in the paragraph. Most questions can have only one correct answer.
question:
Passage: The Covent Garden area has over 60 pubs and bars; several of them are listed buildings, with some also on CAMRA's National Inventory of Historic Pub Interiors; some, such as The Harp in Chandos Place, have received consumer awards. The Harp's awards include London Pub of the Year in 2008 by the Society for the Preservation of Beers from the Wood, and National Pub of the Year by CAMRA in 2010. It was at one time owned by the Charrington Brewery, when it was known as The Welsh Harp; in 1995 the name was abbreviated to just The Harp, before Charrington sold it to Punch Taverns in 1997. It was eventually purchased by the landlady Binnie Walsh around 2010 then subsequently sold by her to Fuller's Brewery in 2014.  It continues to win regular CAMRA pub awards under its new owners.
The Lamb and Flag in Rose Street is possibly the oldest pub in the area. The first mention of a pub on the site is 1772 (when it was called the Cooper's Arms – the name changing to Lamb & Flag in 1833); the 1958 brick exterior conceals what may be an early 18th-century frame of a house replacing the original one built in 1638. The pub acquired a reputation for staging bare-knuckle prize fights during the early 19th century when it earned the nickname "Bucket of Blood". The alleyway beside the pub was the scene of an attack on John Dryden in 1679 by thugs hired by John Wilmot, 2nd Earl of Rochester, with whom he had a long-standing conflict.The Salisbury in St Martin's Lane was built as part of a six-storey block around 1899 on the site of an earlier pub that had been known under several names, including the Coach & Horses and Ben Caunt's Head; it is both Grade II listed, and on CAMRA's National Inventory, due to the quality of the etched and polished glass and the carved woodwork, summed up as "good fin de siècle ensemble". The Freemasons Arms on Long Acre is linked with the founding of the Football Association in 1863; however, the meetings took place at The Freemason's Tavern on Great Queen Street, which was replaced in 1909 by the Connaught Rooms.Other Grade II listed pubs include three 19th century rebuilds of 17th century/18th century houses, the Nell Gwynne Tavern in Bull Inn Court, the Nag's Head on James Street, and the White Swan on New Row; a Victorian pub built by lessees of the Marquis of Exeter, the Old Bell on the corner of Exeter Street and Wellington Street; and a late 18th or early 19th century pub the Angel and Crown on St Martin's Lane. 
Question: What is the current name of the pub that acquired a reputation for staging bare-knuckle prize fights?
answer:
Lamb and Flag.


question:
Passage: Lennon first met Yoko Ono on 9 November 1966 at the Indica Gallery in London, where Ono was preparing her conceptual art exhibit. They were introduced by gallery owner John Dunbar. Lennon was intrigued by Ono's "Hammer A Nail": patrons hammered a nail into a wooden board, creating the art piece. Although the exhibition had not yet begun, Lennon wanted to hammer a nail into the clean board, but Ono stopped him. Dunbar asked her, "Don't you know who this is? He's a millionaire! He might buy it." Ono had supposedly not heard of the Beatles, but relented on condition that Lennon pay her five shillings, to which Lennon replied, "I'll give you an imaginary five shillings and hammer an imaginary nail in." Ono subsequently related that Lennon had taken a bite out of the apple on display in her work Apple, much to her fury.Ono began to telephone and visit Lennon at his home. When Cynthia asked him for an explanation, Lennon explained that Ono was only trying to obtain money for her "avant-garde bullshit". While his wife was on holiday in Greece in May 1968, Lennon invited Ono to visit. They spent the night recording what would become the Two Virgins album, after which, he said, they "made love at dawn". When Lennon's wife returned home she found Ono wearing her bathrobe and drinking tea with Lennon who simply said, "Oh, hi." Ono became pregnant in 1968 and miscarried a male child on 21 November 1968, a few weeks after Lennon's divorce from Cynthia was granted.Two years before the Beatles disbanded, Lennon and Ono began public protests against the Vietnam War. They were married in Gibraltar on 20 March 1969, and spent their honeymoon at the Hilton Amsterdam, campaigning with a week-long Bed-In for Peace. They planned another Bed-In in the United States but were denied entry, so they held one instead at the Queen Elizabeth Hotel in Montreal, where they recorded "Give Peace a Chance". They often combined advocacy with performance art, as in their "Bagism", first introduced during a Vienna press conference. Lennon detailed this period in the Beatles song "The Ballad of John and Yoko". Lennon changed his name by deed poll on 22 April 1969, adding "Ono" as a middle name. The brief ceremony took place on the roof of the Apple Corps building, where the Beatles had performed their rooftop concert three months earlier. Although he used the name John Ono Lennon thereafter, official documents referred to him as John Winston Ono Lennon, since he was not permitted to revoke a name given at birth. The couple settled at Tittenhurst Park at Sunninghill in Berkshire. After Ono was injured in a car accident, Lennon arranged for a king-size bed to be brought to the recording studio as he worked on the Beatles' last album, Abbey Road.Ono and Lennon moved to New York, to a flat on Bank Street, Greenwich Village. Looking for somewhere with better security, they relocated in 1973 to the more secure Dakota overlooking Central Park at 1 West 72nd Street. 
Question: What are the last names of the two individuals who spent the night recording what would become the Two Virgins album?
answer:
Lennon.


question:
Passage: The seabed contains enormous reserves of minerals which can be exploited by dredging. This has advantages over land-based mining in that equipment can be built at specialised shipyards and infrastructure costs are lower. Disadvantages include problems caused by waves and tides, the tendency for excavations to silt up and the washing away of spoil heaps. There is a risk of coastal erosion and environmental damage.
Seafloor massive sulphide deposits are potential sources of silver, gold, copper, lead and zinc and trace metals since their discovery in the 1960s. They form when geothermally heated water is emitted from deep sea hydrothermal vents known as "black smokers". The ores are of high quality but prohibitively costly to extract. Small scale mining of the deep sea floor is being developed off the coast of Papua New Guinea using robotic techniques, but the obstacles are formidable.There are large deposits of petroleum, as oil and natural gas, in rocks beneath the seabed. Offshore platforms and drilling rigs extract the oil or gas and store it for transport to land. Offshore oil and gas production can be difficult due to the remote, harsh environment. Drilling for oil in the sea has environmental impacts. Animals may be disorientated by seismic waves used to locate deposits, probably causing the beaching of whales. Toxic substances such as mercury, lead and arsenic may be released. The infrastructure may cause damage, and oil may be spilt.Large quantities of methane clathrate exist on the seabed and in ocean sediment at a temperature of around 2 °C (36 °F) and these are of interest as a potential energy source. Some estimates put the amount available at between one and 5 million cubic kilometres (0.24 to 1.2 million cubic miles). Also on the seabed are manganese nodules formed of layers of iron, manganese and other hydroxides around a core. In the Pacific these may cover up to 30 percent of the deep ocean floor. The minerals precipitate from seawater and grow very slowly. Their commercial extraction for nickel was investigated in the 1970s but abandoned in favour of more convenient sources. In suitable locations, diamonds are gathered from the seafloor using suction hoses to bring gravel ashore. In deeper waters, mobile seafloor crawlers are used and the deposits are pumped to a vessel above. In Namibia, more diamonds are now collected from marine sources than by conventional methods on land. 
Question: What are of interest as a potential energy source?
answer:

Large quantities of methane clathrate.