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Alpine crystals have been studied and collected for hundreds of years, and began to be classified in the 18th century. Leonhard Euler studied the shapes of crystals, and by the 19th century crystal hunting was common in Alpine regions. David Friedrich Wiser amassed a collection of 8000 crystals that he studied and documented. In the 20th century Robert Parker wrote a well-known work about the rock crystals of the Swiss Alps; at the same period a commission was established to control and standardize the naming of Alpine minerals.
By the 19th century what was common in the Alpine regions?
A: crystal hunting

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In humans and many other mammals, new neurons are created mainly before birth, and the infant brain contains substantially more neurons than the adult brain. There are, however, a few areas where new neurons continue to be generated throughout life. The two areas for which adult neurogenesis is well established are the olfactory bulb, which is involved in the sense of smell, and the dentate gyrus of the hippocampus, where there is evidence that the new neurons play a role in storing newly acquired memories. With these exceptions, however, the set of neurons that is present in early childhood is the set that is present for life. Glial cells are different: as with most types of cells in the body, they are generated throughout the lifespan.
The olfactory bulb is related to what sense?
A: sense of smell

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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).
Who is a celebrity that did not have threats against them?
A: unanswerable

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To varying degrees, Nasser's statist system of government was continued in Egypt and emulated by virtually all Arab republics, namely Algeria, Syria, Iraq, Tunisia, Yemen, Sudan, and Libya. Ahmed Ben Bella, Algeria's first president, was a staunch Nasserist. Abdullah al-Sallal drove out the king of North Yemen in the name of Nasser's pan-Arabism. Other coups influenced by Nasser included those that occurred in Iraq in July 1958 and Syria in 1963. Muammar Gaddafi, who overthrew the Libyan monarchy in 1969, considered Nasser his hero and sought to succeed him as "leader of the Arabs". Also in 1969, Colonel Gaafar Nimeiry, a supporter of Nasser, took power in Sudan. The Arab Nationalist Movement (ANM) helped spread Nasser's pan-Arabist ideas throughout the Arab world, particularly among the Palestinians, Syrians, and Lebanese, and in South Yemen, the Persian Gulf, and Iraq. While many regional heads of state tried to emulate Nasser, Podeh opined that the "parochialism" of successive Arab leaders "transformed imitation [of Nasser] into parody".
What Nasserist usurped the King of Yemen?
A:
Abdullah al-Sallal