Problem: Gun usage in hunting is typically regulated by game category, area within the state, and time period. Regulations for big-game hunting often specify a minimum caliber or muzzle energy for firearms. The use of rifles is often banned for safety reasons in areas with high population densities or limited topographic relief. Regulations may also limit or ban the use of lead in ammunition because of environmental concerns. Specific seasons for bow hunting or muzzle-loading black-powder guns are often established to limit competition with hunters using more effective weapons.
Why are specific seasons for bow hunting established?
The answer is the following: limit competition with hunters using more effective weapons

Problem: Initially sensors were optical and acoustic devices developed during the First World War and continued into the 1930s, but were quickly superseded by radar, which in turn was supplemented by optronics in the 1980s. Command and control remained primitive until the late 1930s, when Britain created an integrated system for ADGB that linked the ground-based air defence of the army's AA Command, although field-deployed air defence relied on less sophisticated arrangements. NATO later called these arrangements an "air defence ground environment", defined as "the network of ground radar sites and command and control centres within a specific theatre of operations which are used for the tactical control of air defence operations".
What country created an integrated system for ADGB?
The answer is the following: Britain

Problem: The medieval city is a foundation of the Zahringer ruling family, which rose to power in Upper Burgundy in the 12th century. According to 14th century historiography (Cronica de Berno, 1309), Bern was founded in 1191 by Berthold V, Duke of Zahringen.
When did the Zahringer ruling family rise to power?
The answer is the following: 12th century

Problem: In the 1960s, Downtown Houston consisted of a collection of mid-rise office structures. Downtown was on the threshold of an energy industryled boom in 1970. A succession of skyscrapers were built throughout the 1970smany by real estate developer Gerald D. Hinesculminating with Houston's tallest skyscraper, the 75-floor, 1,002-foot (305 m)-tall JPMorgan Chase Tower (formerly the Texas Commerce Tower), completed in 1982. It is the tallest structure in Texas, 15th tallest building in the United States, and the 85th tallest skyscraper in the world, based on highest architectural feature. In 1983, the 71-floor, 992-foot (302 m)-tall Wells Fargo Plaza (formerly Allied Bank Plaza) was completed, becoming the second-tallest building in Houston and Texas. Based on highest architectural feature, it is the 17th tallest in the United States and the 95th tallest in the world. In 2007, downtown Houston had over 43 million square feet (4,000,000 m) of office space.
When were skyscrapers first built in Houston?
The answer is the following:
throughout the 1970s