Problem: Infrared:

Earth's surface and the clouds absorb visible and invisible radiation from the sun and re-emit much of the energy as infrared back to atmosphere. Certain substances in the atmosphere, chiefly cloud droplets and water vapor, but also carbon dioxide, methane, nitrous oxide, sulfur hexafluoride, and chlorofluorocarbons, absorb this infrared, and re-radiate it in all directions including back to Earth. Thus, the greenhouse effect keeps the atmosphere and surface much warmer than if the infrared absorbers were absent from the atmosphere.

What does the greenhouse effect absorb from the sun?
---
A: unanswerable

Problem: Namibia:

A combined UN civilian and peace-keeping force called UNTAG (United Nations Transition Assistance Group) under Finnish diplomat Martti Ahtisaari was deployed from April 1989 to March 1990 to monitor the peace process, elections and supervise military withdrawals. As UNTAG began to deploy peacekeepers, military observers, police, and political workers, hostilities were briefly renewed on the day the transition process was supposed to begin. After a new round of negotiations, a second date was set and the elections process began in earnest. After the return of SWAPO exiles (over 46,000 exiles), Namibia's first one-person one-vote elections for the constitutional assembly took place in November 1989. The official election slogan was "Free and Fair Elections". This was won by SWAPO although it did not gain the two-thirds majority it had hoped for; the South African-backed Democratic Turnhalle Alliance (DTA) became the official opposition. The elections were peaceful and declared free and fair.

Who was the head of the SWAPO party?
---
A: unanswerable

Problem: Punjab, Pakistan:

For the popular taste however, light music, particularly Ghazals and folk songs, which have an appeal of their own, the names of Mehdi Hassan, Ghulam Ali, Nur Jehan, Malika Pukhraj, Farida Khanum, Roshen Ara Begum, and Nusrat Fateh Ali Khan are well-known. Folk songs and dances of the Punjab reflect a wide range of moods: the rains, sowing and harvesting seasons. Luddi, Bhangra and Sammi depict the joy of living. Love legends of Heer Ranjha, Mirza Sahiban, Sohni Mahenwal and Saiful Mulk are sung in different styles.

What tends to be less popular with the people?
---
A: unanswerable

Problem: Empiricism:

Mill's empiricism thus held that knowledge of any kind is not from direct experience but an inductive inference from direct experience. The problems other philosophers have had with Mill's position center around the following issues: Firstly, Mill's formulation encounters difficulty when it describes what direct experience is by differentiating only between actual and possible sensations. This misses some key discussion concerning conditions under which such "groups of permanent possibilities of sensation" might exist in the first place. Berkeley put God in that gap; the phenomenalists, including Mill, essentially left the question unanswered. In the end, lacking an acknowledgement of an aspect of "reality" that goes beyond mere "possibilities of sensation", such a position leads to a version of subjective idealism. Questions of how floor beams continue to support a floor while unobserved, how trees continue to grow while unobserved and untouched by human hands, etc., remain unanswered, and perhaps unanswerable in these terms. Secondly, Mill's formulation leaves open the unsettling possibility that the "gap-filling entities are purely possibilities and not actualities at all". Thirdly, Mill's position, by calling mathematics merely another species of inductive inference, misapprehends mathematics. It fails to fully consider the structure and method of mathematical science, the products of which are arrived at through an internally consistent deductive set of procedures which do not, either today or at the time Mill wrote, fall under the agreed meaning of induction.

What do indirect experiences produce?
---
A:
unanswerable