Article: The Eastern Han, also known as the Later Han, formally began on 5 August 25, when Liu Xiu became Emperor Guangwu of Han. During the widespread rebellion against Wang Mang, the state of Goguryeo was free to raid Han's Korean commanderies; Han did not reaffirm its control over the region until AD 30. The Trung Sisters of Vietnam rebelled against Han in AD 40. Their rebellion was crushed by Han general Ma Yuan (d. AD 49) in a campaign from AD 4243. Wang Mang renewed hostilities against the Xiongnu, who were estranged from Han until their leader Bi (), a rival claimant to the throne against his cousin Punu (), submitted to Han as a tributary vassal in AD 50. This created two rival Xiongnu states: the Southern Xiongnu led by Bi, an ally of Han, and the Northern Xiongnu led by Punu, an enemy of Han.

Question: Who was the leader of the Xiongnu?
Ans: Bi

Article: Different pieces of wood cut from a large tree may differ decidedly, particularly if the tree is big and mature. In some trees, the wood laid on late in the life of a tree is softer, lighter, weaker, and more even-textured than that produced earlier, but in other trees, the reverse applies. This may or may not correspond to heartwood and sapwood. In a large log the sapwood, because of the time in the life of the tree when it was grown, may be inferior in hardness, strength, and toughness to equally sound heartwood from the same log. In a smaller tree, the reverse may be true.

Question: Besides big trees, what trees are more likely to have a range of different kinds of wood?
Ans: mature

Article: The terms asphalt and bitumen are often used interchangeably to mean both natural and manufactured forms of the substance. In American English, asphalt (or asphalt cement) is the carefully refined residue from the distillation process of selected crude oils. Outside the United States, the product is often called bitumen. Geologists often prefer the term bitumen. Common usage often refers to various forms of asphalt/bitumen as "tar", such as at the La Brea Tar Pits. Another archaic term for asphalt/bitumen is "pitch".

Question: Where is bitumen the usual term for refined residue from crude oils?
Ans: United States

Article: The FBI has maintained files on numerous people, including celebrities such as Elvis Presley, Frank Sinatra, John Denver, John Lennon, Jane Fonda, Groucho Marx, Charlie Chaplin, the band MC5, Lou Costello, Sonny Bono, Bob Dylan, Michael Jackson, and Mickey Mantle. The files were collected for various reasons. Some of the subjects were investigated for alleged ties to the Communist party (Charlie Chaplin and Groucho Marx), or in connection with antiwar activities during the Vietnam War (John Denver, John Lennon, and Jane Fonda). Numerous celebrity files concern threats or extortion attempts against them (Sonny Bono, John Denver, John Lennon, Elvis Presley, Michael Jackson, Mickey Mantle, Groucho Marx, and Frank Sinatra).

Question: Did the FBI keep files on Elvis Presley?
Ans:
including celebrities such as Elvis Presley