instruction:
This task is about reading the given passage and construct a question about the information present in the passage. Construct a question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) its answer is a continuous text span from the paragraph. Avoid creating questions that (i) can be answered correctly without actually understanding the paragraph and (ii) uses same words or phrases given in the passage.
question:
Tower Control controls aircraft on the runway and in the controlled airspace immediately surrounding the airport. Tower controllers may use radar to locate an aircraft's position in three-dimensional space, or they may rely on pilot position reports and visual observation. They coordinate the sequencing of aircraft in the traffic pattern and direct aircraft on how to safely join and leave the circuit. Aircraft which are only passing through the airspace must also contact Tower Control in order to be sure that they remain clear of other traffic.
answer:
Who controls aircraft on the runway?


question:
A significant modification of Cubism between 1914 and 1916 was signaled by a shift towards a strong emphasis on large overlapping geometric planes and flat surface activity. This grouping of styles of painting and sculpture, especially significant between 1917 and 1920, was practiced by several artists; particularly those under contract with the art dealer and collector Léonce Rosenberg. The tightening of the compositions, the clarity and sense of order reflected in these works, led to its being referred to by the critic Maurice Raynal (fr) as 'crystal' Cubism. Considerations manifested by Cubists prior to the outset of World War I—such as the fourth dimension, dynamism of modern life, the occult, and Henri Bergson's concept of duration—had now been vacated, replaced by a purely formal frame of reference.
answer:
What did the critic Maurice Raynal begin to refer to Cubism in around 1917-1920?


question:
This unified institution consists of sea, land, and air elements referred to as the Royal Canadian Navy (RCN), Canadian Army, and Royal Canadian Air Force (RCAF). Personnel may belong to either the Regular Force or the Reserve Force, which has four sub-components: the Primary Reserve, Supplementary Reserve, Cadet Organizations Administration and Training Service, and the Canadian Rangers. Under the National Defence Act, the Canadian Armed Forces are an entity separate and distinct from the Department of National Defence (the federal government department responsible for administration and formation of defence policy), which also exists as the civilian support system for the Forces.
answer:

How many sub components are there?