Here is a question about this article: In the United States, heating, ventilation and air conditioning (HVAC) systems account for 30% (4.65 EJ/yr) of the energy used in commercial buildings and nearly 50% (10.1 EJ/yr) of the energy used in residential buildings. Solar heating, cooling and ventilation technologies can be used to offset a portion of this energy.
What is the answer to this question: What percentage of energy in commercial buildings comes from HVAC systems?
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So... 50

Here is a question about this article: Expansive interior light has been a feature of Gothic cathedrals since the first structure was opened. The metaphysics of light in the Middle Ages led to clerical belief in its divinity and the importance of its display in holy settings. Much of this belief was based on the writings of Pseudo-Dionysius, a sixth-century mystic whose book, The Celestial Hierarchy, was popular among monks in France. Pseudo-Dionysius held that all light, even light reflected from metals or streamed through windows, was divine. To promote such faith, the abbot in charge of the Saint-Denis church on the north edge of Paris, the Abbot Suger, encouraged architects remodeling the building to make the interior as bright as possible.
What is the answer to this question: Who encouraged cathedral architects to allow as much light as possible into the building?
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So... the Abbot Suger

Here is a question about this article: John, the youngest of five sons of King Henry II of England and Eleanor of Aquitaine, was at first not expected to inherit significant lands. Following the failed rebellion of his elder brothers between 1173 and 1174, however, John became Henry's favourite child. He was appointed the Lord of Ireland in 1177 and given lands in England and on the continent. John's elder brothers William, Henry and Geoffrey died young; by the time Richard I became king in 1189, John was a potential heir to the throne. John unsuccessfully attempted a rebellion against Richard's royal administrators whilst his brother was participating in the Third Crusade. Despite this, after Richard died in 1199, John was proclaimed King of England, and came to an agreement with Philip II of France to recognise John's possession of the continental Angevin lands at the peace treaty of Le Goulet in 1200.
What is the answer to this question: When was John appointed the Lord of Ireland?
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So...
1177