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Canadian bitumen does not differ substantially from oils such as Venezuelan extra-heavy and Mexican heavy oil in chemical composition, and the real difficulty is moving the extremely viscous bitumen through oil pipelines to the refinery. Many modern oil refineries are extremely sophisticated and can process non-upgraded bitumen directly into products such as gasoline, diesel fuel, and refined asphalt without any preprocessing. This is particularly common in areas such as the US Gulf coast, where refineries were designed to process Venezuelan and Mexican oil, and in areas such as the US Midwest where refineries were rebuilt to process heavy oil as domestic light oil production declined. Given the choice, such heavy oil refineries usually prefer to buy bitumen rather than synthetic oil because the cost is lower, and in some cases because they prefer to produce more diesel fuel and less gasoline. By 2015 Canadian production and exports of non-upgraded bitumen exceeded that of synthetic crude oil at over 1.3 million barrels (210×10^3 m3) per day, of which about 65% was exported to the United States.

What property of bitumen makes it difficult to move through pipelines?
Answer: extremely viscous
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At the very end of the 19th century, a new style, with a carved top and back construction inspired by violin family instruments began to supplant the European-style bowl-back instruments in the United States. This new style is credited to mandolins designed and built by Orville Gibson, a Kalamazoo, Michigan luthier who founded the "Gibson Mandolin-Guitar Manufacturing Co., Limited" in 1902. Gibson mandolins evolved into two basic styles: the Florentine or F-style, which has a decorative scroll near the neck, two points on the lower body and usually a scroll carved into the headstock; and the A-style, which is pear shaped, has no points and usually has a simpler headstock.

When was a new sytle of carved top and back construction mandolins created?
Answer: end of the 19th century
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Green can communicate safety to proceed, as in traffic lights. Green and red were standardized as the colors of international railroad signals in the 19th century. The first traffic light, using green and red gas lamps, was erected in 1868 in front of the Houses of Parliament in London. It exploded the following year, injuring the policeman who operated it. In 1912, the first modern electric traffic lights were put up in Salt Lake City, Utah. Red was chosen largely because of its high visibility, and its association with danger, while green was chosen largely because it could not be mistaken for red. Today green lights universally signal that a system is turned on and working as it should. In many video games, green signifies both health and completed objectives, opposite red.

Besides its association with danger, why was red chosen for traffic lights?
Answer:
high visibility