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.

Ex Input:
Passage: Eritrea has achieved significant improvements in health care and is one of the few countries to be on target to meet its Millennium Development Goal (MDG) targets in health, in particular child health. Life expectancy at birth has increased from 39.1 in 1960 to 59.5 years in 2008, maternal and child mortality rates have dropped dramatically and the health infrastructure has been expanded. Due to Eritrea's relative isolation, information and resources are extremely limited and according to the World Health Organisation (WHO) found in 2008 average life expectancy to be slightly less than 63 years. Immunisation and child nutrition has been tackled by working closely with schools in a multi-sectoral approach; the number of children vaccinated against measles almost doubled in seven years, from 40.7% to 78.5% and the underweight prevalence among children decreased by 12% in 19952002 (severe underweight prevalence by 28%). The National Malaria Protection Unit of the Ministry of Health has registered tremendous improvements in reducing malarial mortality by as much as 85% and the number of cases by 92% between 1998 and 2006. The Eritrean government has banned female genital mutilation (FGM), saying the practice was painful and put women at risk of life-threatening health problems.

Ex Output:
In what year was female genital mutilation banned in Eretria?

Ex Input:
Passage: An alloy is a mixture of metals or a mixture of a metal and another element. Alloys are defined by metallic bonding character. An alloy may be a solid solution of metal elements (a single phase) or a mixture of metallic phases (two or more solutions). Intermetallic compounds are alloys with a defined stoichiometry and crystal structure. Zintl phases are also sometimes considered alloys depending on bond types (see also: Van Arkel-Ketelaar triangle for information on classifying bonding in binary compounds).

Ex Output:
What is always a mixture of metal and other elements?

Ex Input:
Passage: In principle, the Planck constant could be determined by examining the spectrum of a black-body radiator or the kinetic energy of photoelectrons, and this is how its value was first calculated in the early twentieth century. In practice, these are no longer the most accurate methods. The CODATA value quoted here is based on three watt-balance measurements of KJ2RK and one inter-laboratory determination of the molar volume of silicon, but is mostly determined by a 2007 watt-balance measurement made at the U.S. National Institute of Standards and Technology (NIST). Five other measurements by three different methods were initially considered, but not included in the final refinement as they were too imprecise to affect the result.

Ex Output:
What year was the measurement for the Planck constant value avoided?