Article: The majority of the world's airports are non-towered, with no air traffic control presence. Busy airports have air traffic control (ATC) system. All airports use a traffic pattern to assure smooth traffic flow between departing and arriving aircraft. There are a number of aids available to pilots, though not all airports are equipped with them. Many airports have lighting that help guide planes using the runways and taxiways at night or in rain, snow, or fog. In the U.S. and Canada, the vast majority of airports, large and small, will either have some form of automated airport weather station, a human observer or a combination of the two. Air safety is an important concern in the operation of an airport, and airports often have their own safety services.

Question: What is an important concern in the operation of an airport?
Ans: Air safety


Here is a question about this article: This flexibility allows Catalan to use extraposition extensively, much more than French or Spanish. Thus, Catalan can have m'hi recomanaren ("they recommended me to him"), whereas in French one must say ils m'ont recommandé à lui, and Spanish me recomendaron a él. This allows the placement of almost any nominal term as a sentence topic, without having to use so often the passive voice (as in French or English), or identifying the direct object with a preposition (as in Spanish).
What is the answer to this question: What method does Spanish use to identify the object?
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So... preposition


The problem: Answer a question about this article:
The roots of Orthodox Judaism can be traced to the late 18th or early 19th century, when elements within German Jewry sought to reform Jewish belief and practice in the early 19th century in response to the Age of Enlightenment, Jewish Emancipation, and Haskalah. They sought to modernize education in light of contemporary scholarship. They rejected claims of the absolute divine authorship of the Torah, declaring only biblical laws concerning ethics to be binding, and stated that the rest of halakha (Jewish law) need not be viewed as normative for Jews in wider society. (see Reform Judaism).
When did the German Jewry seek to reform Jewish belief?
****
The answer: early 19th century


Problem: Please answer a question about the following article about Alaska:
Another Alaskan transportation method is the dogsled. In modern times (that is, any time after the mid-late 1920s), dog mushing is more of a sport than a true means of transportation. Various races are held around the state, but the best known is the Iditarod Trail Sled Dog Race, a 1,150-mile (1,850 km) trail from Anchorage to Nome (although the distance varies from year to year, the official distance is set at 1,049 miles or 1,688 km). The race commemorates the famous 1925 serum run to Nome in which mushers and dogs like Togo and Balto took much-needed medicine to the diphtheria-stricken community of Nome when all other means of transportation had failed. Mushers from all over the world come to Anchorage each March to compete for cash, prizes, and prestige. The "Serum Run" is another sled dog race that more accurately follows the route of the famous 1925 relay, leaving from the community of Nenana (southwest of Fairbanks) to Nome.
Which dogsled race most accurately follows the route of the 1925 serum run?
A: "Serum Run"


Question: Read this and answer the question

The Philippines has had small grassroots movements for U.S. statehood. Originally part of the platform of the Progressive Party, then known as the Federalista Party, the party dropped it in 1907, which coincided with the name change. As recently as 2004, the concept of the Philippines becoming a U.S. state has been part of a political platform in the Philippines. Supporters of this movement include Filipinos who believe that the quality of life in the Philippines would be higher and that there would be less poverty there if the Philippines were an American state or territory. Supporters also include Filipinos that had fought as members of the United States Armed Forces in various wars during the Commonwealth period.

What party used to be known as the Federalista Party?
Answer: Federalista Party


The concentration of copper in ores averages only 0.6%, and most commercial ores are sulfides, especially chalcopyrite (CuFeS2) and to a lesser extent chalcocite (Cu2S). These minerals are concentrated from crushed ores to the level of 10–15% copper by froth flotation or bioleaching. Heating this material with silica in flash smelting removes much of the iron as slag. The process exploits the greater ease of converting iron sulfides into its oxides, which in turn react with the silica to form the silicate slag, which floats on top of the heated mass. The resulting copper matte consisting of Cu2S is then roasted to convert all sulfides into oxides:
What happens to the silicate slag  during the flash smelting process?
floats on top