Question: The BeiDou Navigation Satellite System (BDS, simplified Chinese: ; traditional Chinese: ; pinyin: Beidou weixing daohang xitong) is a Chinese satellite navigation system. It consists of two separate satellite constellations a limited test system that has been operating since 2000, and a full-scale global navigation system that is currently under construction.
Is there an answer to this question: Which system is no longer under construction?

Answer: unanswerable

Question: Nasser's involvement in political activity increased throughout his school years, such that he only attended 45 days of classes during his last year of secondary school. Despite it having the almost unanimous backing of Egypt's political forces, Nasser strongly objected to the 1936 Anglo-Egyptian Treaty because it stipulated the continued presence of British military bases in the country. Nonetheless, political unrest in Egypt declined significantly and Nasser resumed his studies at al-Nahda, where he received his leaving certificate later that year.
Is there an answer to this question: How many days did Nasser attend classes in his senior year?

Answer: 45

Question: By the twentieth century, the U.S. Army had mobilized the U.S. Volunteers on four separate occasions during each of the major wars of the nineteenth century. During World War I, the "National Army" was organized to fight the conflict, replacing the concept of U.S. Volunteers. It was demobilized at the end of World War I, and was replaced by the Regular Army, the Organized Reserve Corps, and the State Militias. In the 1920s and 1930s, the "career" soldiers were known as the "Regular Army" with the "Enlisted Reserve Corps" and "Officer Reserve Corps" augmented to fill vacancies when needed.
Is there an answer to this question: When was the National Army demobilized?

Answer: end of World War I

Question: Since 1947, Canadian military units have participated in more than 200 operations worldwide, and completed 72 international operations. Canadian soldiers, sailors, and aviators came to be considered world-class professionals through conspicuous service during these conflicts and the country's integral participation in NATO during the Cold War, First Gulf War, Kosovo War, and in United Nations Peacekeeping operations, such as the Suez Crisis, Golan Heights, Cyprus, Croatia, Bosnia, Afghanistan, and Libya. Canada maintained an aircraft carrier from 1957 to 1970 during the Cold War, which never saw combat but participated in patrols during the Cuban Missile Crisis.
Is there an answer to this question: What are some of the wars the Canadian Military was involved in?

Answer:
Cold War, First Gulf War, Kosovo War