This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.

Passage: For instance, a common use of a database system is to track information about users, their name, login information, various addresses and phone numbers. In the navigational approach all of this data would be placed in a single record, and unused items would simply not be placed in the database. In the relational approach, the data would be normalized into a user table, an address table and a phone number table (for instance). Records would be created in these optional tables only if the address or phone numbers were actually provided.
How is a database system rarely used?

Passage: Mali lies in the torrid zone and is among the hottest countries in the world. The thermal equator, which matches the hottest spots year-round on the planet based on the mean daily annual temperature, crosses the country. Most of Mali receives negligible rainfall and droughts are very frequent. Late June to early December is the rainy season in the southernmost area. During this time, flooding of the Niger River is common, creating the Inner Niger Delta. The vast northern desert part of Mali has a hot desert climate (Köppen climate classification (BWh) with long, extremely hot summers and scarce rainfall which decreases northwards. The central area has a hot semi-arid climate (Köppen climate classification (BSh) with very high temperatures year-round, a long, intense dry season and a brief, irregular rainy season. The little southern band possesses a tropical wet and dry climate (Köppen climate classification (Aw) very high temperatures year-round with a dry season and a rainy season.
What is in the tropical zone?

Passage: Harvard was formed in 1636 by vote of the Great and General Court of the Massachusetts Bay Colony. It was initially called "New College" or "the college at New Towne". In 1638, the college became home for North America's first known printing press, carried by the ship John of London. In 1639, the college was renamed Harvard College after deceased clergyman John Harvard, who was an alumnus of the University of Cambridge. He had left the school £779 and his library of some 400 books. The charter creating the Harvard Corporation was granted in 1650.

What was the ship of John of London called?