Input: Article: A solar chimney (or thermal chimney, in this context) is a passive solar ventilation system composed of a vertical shaft connecting the interior and exterior of a building. As the chimney warms, the air inside is heated causing an updraft that pulls air through the building. Performance can be improved by using glazing and thermal mass materials in a way that mimics greenhouses.

Now answer this question: What kind of system is a solar chimney?

Output: passive solar ventilation

Input: Article: On the afternoon of Gaddafi's death, NTC Prime Minister Mahmoud Jibril publicly revealed the news. Gaddafi's corpse was placed in the freezer of a local market alongside the corpses of Yunis Jabr and Mutassim; the bodies were publicly displayed for four days, with Libyans from all over the country coming to view them. In response to international calls, on 24 October Jibril announced that a commission would investigate Gaddafi's death. On 25 October, the NTC announced that Gaddafi had been buried at an unidentified location in the desert; Al Aan TV showed amateur video footage of the funeral. Seeking vengeance for the killing, Gaddafist sympathisers fatally wounded one of those who had captured Gaddafi, Omran Shaaban, near Bani Walid in September 2012.

Now answer this question: For how many days was Gaddafi's corpse displayed in public?

Output: four

Input: Article: Replicated CDs are mass-produced initially using a hydraulic press. Small granules of heated raw polycarbonate plastic are fed into the press. A screw forces the liquefied plastic into the mold cavity. The mold closes with a metal stamper in contact with the disc surface. The plastic is allowed to cool and harden. Once opened, the disc substrate is removed from the mold by a robotic arm, and a 15 mm diameter center hole (called a stacking ring) is created. The time it takes to "stamp" one CD is usually two to three seconds.

Now answer this question: What is the term for the center hole in a CD?

Output:
stacking ring