Problem: Infrared radiation is used in industrial, scientific, and medical applications. Night-vision devices using active near-infrared illumination allow people or animals to be observed without the observer being detected. Infrared astronomy uses sensor-equipped telescopes to penetrate dusty regions of space, such as molecular clouds; detect objects such as planets, and to view highly red-shifted objects from the early days of the universe. Infrared thermal-imaging cameras are used to detect heat loss in insulated systems, to observe changing blood flow in the skin, and to detect overheating of electrical apparatus.
What technology is used by night-vision devices?
The answer is the following: active near-infrared illumination

Problem: Other sections of society included the nobility, clergy, and townsmen. Nobles, both the titled nobility and simple knights, exploited the manors and the peasants, although they did not own lands outright but were granted rights to the income from a manor or other lands by an overlord through the system of feudalism. During the 11th and 12th centuries, these lands, or fiefs, came to be considered hereditary, and in most areas they were no longer divisible between all the heirs as had been the case in the early medieval period. Instead, most fiefs and lands went to the eldest son.[R] The dominance of the nobility was built upon its control of the land, its military service as heavy cavalry, control of castles, and various immunities from taxes or other impositions.[S] Castles, initially in wood but later in stone, began to be constructed in the 9th and 10th centuries in response to the disorder of the time, and provided protection from invaders as well as allowing lords defence from rivals. Control of castles allowed the nobles to defy kings or other overlords. Nobles were stratified; kings and the highest-ranking nobility controlled large numbers of commoners and large tracts of land, as well as other nobles. Beneath them, lesser nobles had authority over smaller areas of land and fewer people. Knights were the lowest level of nobility; they controlled but did not own land, and had to serve other nobles.[T]
In what century were castles first built?
The answer is the following: 9th

Problem: Public buildings generally varied between the extremes of plain boxes with grid windows and Italian Late Renaissance palaces, depending on budget. Somerset House in London, designed by Sir William Chambers in 1776 for government offices, was as magnificent as any country house, though never quite finished, as funds ran out. Barracks and other less prestigious buildings could be as functional as the mills and factories that were growing increasingly large by the end of the period. But as the period came to an end many commercial projects were becoming sufficiently large, and well-funded, to become "architectural in intention", rather than having their design left to the lesser class of "surveyors".
Commercial projects in the late period tended to be "architectural" in what way?
The answer is the following: "architectural in intention"

Problem: In Europe the Wayback Machine could be interpreted as violating copyright laws. Only the content creator can decide where their content is published or duplicated, so the Archive would have to delete pages from its system upon request of the creator. The exclusion policies for the Wayback Machine may be found in the FAQ section of the site. The Wayback Machine also retroactively respects robots.txt files, i.e., pages that currently are blocked to robots on the live web temporarily will be made unavailable from the archives as well.
What kinds of laws could the Wayback Machine be viewed as breaking in Europe?
The answer is the following:
copyright laws