instruction:
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.
question:
Passage: As the Grand Duchy of Finland was part of the Russian Empire from 1809 to 1918, a number of Russian speakers have remained in Finland. There are 33,400 Russian-speaking Finns, amounting to 0.6% of the population. Five thousand (0.1%) of them are late 19th century and 20th century immigrants or their descendants, and the remaining majority are recent immigrants who moved there in the 1990s and later.[citation needed] Russian is spoken by 1.4% of the population of Finland according to a 2014 estimate from the World Factbook.
answer:
When did immigrants form the Russian Empire?


question:
Passage: Uranium was also used in photographic chemicals (especially uranium nitrate as a toner), in lamp filaments for stage lighting bulbs, to improve the appearance of dentures, and in the leather and wood industries for stains and dyes. Uranium salts are mordants of silk or wool. Uranyl acetate and uranyl formate are used as electron-dense "stains" in transmission electron microscopy, to increase the contrast of biological specimens in ultrathin sections and in negative staining of viruses, isolated cell organelles and macromolecules.
answer:
What product of uranium wasn't used as toner?


question:
Passage: The prognosis for asthma is generally good, especially for children with mild disease. Mortality has decreased over the last few decades due to better recognition and improvement in care. Globally it causes moderate or severe disability in 19.4 million people as of 2004 (16 million of which are in low and middle income countries). Of asthma diagnosed during childhood, half of cases will no longer carry the diagnosis after a decade. Airway remodeling is observed, but it is unknown whether these represent harmful or beneficial changes. Early treatment with corticosteroids seems to prevent or ameliorates a decline in lung function.
answer:

What is the prognosis after treating airway remodeling?