Input: Read this: Numerous communities of dark-skinned peoples are present in North Africa, some dating from prehistoric communities. Others are descendants of the historical Trans-Saharan trade in peoples and/or, and after the Arab invasions of North Africa in the 7th century, descendants of slaves from the Arab Slave Trade in North Africa.
Question: Where were numerous dark-skinned communities?

Output: North Africa

Input: Read this: In 1943, at the age of 16, Elizabeth undertook her first solo public appearance on a visit to the Grenadier Guards, of which she had been appointed colonel the previous year. As she approached her 18th birthday, parliament changed the law so that she could act as one of five Counsellors of State in the event of her father's incapacity or absence abroad, such as his visit to Italy in July 1944. In February 1945, she joined the Women's Auxiliary Territorial Service as an honorary second subaltern with the service number of 230873. She trained as a driver and mechanic and was promoted to honorary junior commander five months later.
Question: In what year was the Grenadier Guards started?

Output: unanswerable

Input: Read this: The Union Internationale des Associations d'Alpinisme (UIAA) has defined a list of 82 "official" Alpine summits that reach at least 4,000 m (13,123 ft). The list includes not only mountains, but also subpeaks with little prominence that are considered important mountaineering objectives. Below are listed the 22 "four-thousanders" with at least 500 m (1,640 ft) of prominence.
Question: What group defined a list of 82 official Apline summits that reach 4,000m?

Output: Union Internationale des Associations d'Alpinisme (UIAA)

Input: Read this: The convention followed by many British publishers (including scientific publishers, like Nature, magazines, like The Economist and New Scientist, and newspapers, like The Guardian and The Times) and U.S. newspapers is to use sentence-style capitalisation in headlines, where capitalisation follows the same rules that apply for sentences. This convention is usually called sentence case. It may also be applied to publication titles, especially in bibliographic references and library catalogues. Examples of global publishers whose English-language house styles prescribe sentence-case titles and headings include the International Organization for Standardization.
Question: Which popular global publisher utilizes sentence case for titles and headers?

Output:
International Organization for Standardization