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.
One example: Passage: The French and Indian War (1754–1763) was the North American theater of the worldwide Seven Years' War. The war was fought between the colonies of British America and New France, with both sides supported by military units from their parent countries of Great Britain and France, as well as Native American allies. At the start of the war, the French North American colonies had a population of roughly 60,000 European settlers, compared with 2 million in the British North American colonies. The outnumbered French particularly depended on the Indians. Long in conflict, the metropole nations declared war on each other in 1756, escalating the war from a regional affair into an intercontinental conflict.
Solution is here: When was the French and Indian War?
Explanation: This question is based on the following sentence in the passage- The French and Indian War (1754–1763) was the North American theater of the worldwide Seven Years' War. It is a common convention to write (start year-end year) beside a historical event to understand when the event happened. You can ask questions like this one about dates, years, other numerals, persons, locations, noun phrases, verb phrases, adjectives, clauses etc. which exist in the paragraph.

Now, solve this: The area north of the Congo River came under French sovereignty in 1880 as a result of Pierre de Brazza's treaty with Makoko of the Bateke. This Congo Colony became known first as French Congo, then as Middle Congo in 1903. In 1908, France organized French Equatorial Africa (AEF), comprising Middle Congo, Gabon, Chad, and Oubangui-Chari (the modern Central African Republic). The French designated Brazzaville as the federal capital. Economic development during the first 50 years of colonial rule in Congo centered on natural-resource extraction. The methods were often brutal: construction of the Congo–Ocean Railroad following World War I has been estimated to have cost at least 14,000 lives.
Solution:
When did the French take control of the region to the north of the Congo River?