Input: Read this: Contemporary a cappella includes many vocal groups and bands who add vocal percussion or beatboxing to create a pop/rock/gospel sound, in some cases very similar to bands with instruments. Examples of such professional groups include Straight No Chaser, Pentatonix, The House Jacks, Rockapella, Mosaic, and M-pact. There also remains a strong a cappella presence within Christian music, as some denominations purposefully do not use instruments during worship. Examples of such groups are Take 6, Glad and Acappella. Arrangements of popular music for small a cappella ensembles typically include one voice singing the lead melody, one singing a rhythmic bass line, and the remaining voices contributing chordal or polyphonic accompaniment.
Question: What do some a cappella groups use instead of chordal accompanyment?

Output: unanswerable

Input: Read this: The Atlantic Ocean has less influence on the climate of the Piedmont region, which has hotter summers and colder winters than in the coast. Daytime highs in the Piedmont often reach over 90 F (32 C) in the summer. While it is not common for the temperature to reach over 100 F (38 C) in the state, such temperatures, when they occur, typically are found only in the lower-elevation areas of the Piedmont and far-inland areas of the coastal plain. The weaker influence of the Atlantic Ocean also means that temperatures in the Piedmont often fluctuate more widely than in the coast.
Question: Temperatures over 100 degrees will typically be found in what elevation of the Piedmont?

Output: .

Input: Read this: It was temporarily under the control of the Tibetan empire and Chinese from 650680 and then under the control of the Umayyads in 710. The Samanid Empire, 819 to 999, restored Persian control of the region and enlarged the cities of Samarkand and Bukhara (both cities are today part of Uzbekistan) which became the cultural centers of Iran and the region was known as Khorasan. The Kara-Khanid Khanate conquered Transoxania (which corresponds approximately with modern-day Uzbekistan, Tajikistan, southern Kyrgyzstan and southwest Kazakhstan) and ruled between 9991211. Their arrival in Transoxania signaled a definitive shift from Iranian to Turkic predominance in Central Asia, but gradually the Kara-khanids became assimilated into the Perso-Arab Muslim culture of the region.
Question: When did the Samanid Empire rule the land?

Output: The Samanid Empire

Input: Read this: On 16 September 2001, at Camp David, President George W. Bush used the phrase war on terrorism in an unscripted and controversial comment when he said, "This crusade this war on terrorism is going to take a while, ... " Bush later apologized for this remark due to the negative connotations the term crusade has to people, e.g. of Muslim faith. The word crusade was not used again. On 20 September 2001, during a televised address to a joint session of congress, Bush stated that, "(o)ur 'war on terror' begins with al-Qaeda, but it does not end there. It will not end until every terrorist group of global reach has been found, stopped, and defeated."
Question: Where did George W. Bush give his 20 September 2001 address from?

Output:
unanswerable