Problem: Please answer a question about the following article about Alexander Graham Bell:
In 1898, Bell experimented with tetrahedral box kites and wings constructed of multiple compound tetrahedral kites covered in maroon silk.[N 23] The tetrahedral wings were named Cygnet I, II and III, and were flown both unmanned and manned (Cygnet I crashed during a flight carrying Selfridge) in the period from 19071912. Some of Bell's kites are on display at the Alexander Graham Bell National Historic Site.
Bell's kits were flown from 1907 to what year?
A: 1912
Problem: Please answer a question about the following article about Estonian language:
The domination of Estonia after the Northern Crusades, from the 13th century to 1918 by Denmark, Germany, Sweden, and Russia delayed indigenous literacy in Estonia.[citation needed]
What did the aftermath of the crusades end up delaying in Estonia?
A: indigenous literacy
Problem: Please answer a question about the following article about Antenna (radio):
Reflection of the original signal also occurs when it hits an extended conductive surface, in a fashion similar to a mirror. This effect can also be used to increase signal through the use of a reflector, normally placed behind the active element and spaced so the reflected signal reaches the element in-phase. Generally the reflector will remain highly reflective even if it is not solid; gaps less than 110 generally have little effect on the outcome. For this reason, reflectors often take the form of wire meshes or rows of passive elements, which makes them lighter and less subject to wind. The parabolic reflector is perhaps the best known example of a reflector-based antenna, which has an effective area far greater than the active element alone.
What is the most recognized type of an antenna that has its basis in reflection?
A: parabolic reflector
Problem: Please answer a question about the following article about Franco-Prussian War:
Despite odds of four to one, the III Corps launched a risky attack. The French were routed and the III Corps captured Vionville, blocking any further escape attempts to the west. Once blocked from retreat, the French in the fortress of Metz had no choice but to engage in a fight that would see the last major cavalry engagement in Western Europe. The battle soon erupted, and III Corps was shattered by incessant cavalry charges, losing over half its soldiers. The German Official History recorded 15,780 casualties and French casualties of 13,761 men.
With battle at Metz, what factor shattered the efforts of III Corps?
A:
incessant cavalry charges