Input: Read this: In 1790, the first federal population census was taken in the United States. Enumerators were instructed to classify free residents as white or "other." Only the heads of households were identified by name in the federal census until 1850. Native Americans were included among "Other;" in later censuses, they were included as "Free people of color" if they were not living on Indian reservations. Slaves were counted separately from free persons in all the censuses until the Civil War and end of slavery. In later censuses, people of African descent were classified by appearance as mulatto (which recognized visible European ancestry in addition to African) or black.
Question: What year was the last federal population census taken in the United States?

Output: unanswerable

Input: Read this: After the war, Feynman declined an offer from the Institute for Advanced Study in Princeton, New Jersey, despite the presence there of such distinguished faculty members as Albert Einstein, Kurt Godel and John von Neumann. Feynman followed Hans Bethe, instead, to Cornell University, where Feynman taught theoretical physics from 1945 to 1950. During a temporary depression following the destruction of Hiroshima by the bomb produced by the Manhattan Project, he focused on complex physics problems, not for utility, but for self-satisfaction. One of these was analyzing the physics of a twirling, nutating dish as it is moving through the air. His work during this period, which used equations of rotation to express various spinning speeds, proved important to his Nobel Prizewinning work, yet because he felt burned out and had turned his attention to less immediately practical problems, he was surprised by the offers of professorships from other renowned universities.
Question: Which college did Feynman always have a job in?

Output: unanswerable

Input: Read this: Most common glass contains other ingredients to change its properties. Lead glass or flint glass is more 'brilliant' because the increased refractive index causes noticeably more specular reflection and increased optical dispersion. Adding barium also increases the refractive index. Thorium oxide gives glass a high refractive index and low dispersion and was formerly used in producing high-quality lenses, but due to its radioactivity has been replaced by lanthanum oxide in modern eyeglasses.[citation needed] Iron can be incorporated into glass to absorb infrared energy, for example in heat absorbing filters for movie projectors, while cerium(IV) oxide can be used for glass that absorbs UV wavelengths.
Question: What property of thorium oxide has caused it to no longer be used in eyeglasses?

Output: radioactivity

Input: Read this: Improved sanitation in the developing world is a global need, but a neglected priority as shown by the data collected by the Joint Monitoring Programme for Water Supply and Sanitation (JMP) of UNICEF and WHO. This program is tasked to monitor progress towards the Millennium Development Goal (MDG) relating to drinking water and sanitation. About one billion people have no sanitation facility whatsoever and continue to defecate in gutters, behind bushes or in open water bodies, with no dignity or privacy - which is called open defecation and which poses significant health risks. India is the country with the highest number of people practicing open defecation: around 600 million people. India has also become a focus country for the foundation's sanitation activities which has become evident since the "Reinvent the Toilet Fair" in Delhi, India in March 2014.
Question: What country is the worst violator

Output:
India is the country with the highest number of people practicing open defecation: around 600 million people