Which of the following correctly describes the general process of coal mining and refining? select one: a. coal is mined, washed, dried, and then separated from rock particles. b. coal is mined, dryed, and crushed. c. coal is mined, moved along a conveyor belt, mixed with water, then dried.

The general process for coal mining and refining is option C.

Coal mining is carried out by two main processes based on the depth, quality, thickness, and structure of coal seam. Based on the depth, coal seam of less than 180ft to the surface is surface mined while coal seems between 180ft.-300ft. are deep mined. The coal mined is transported to a nearby processing plant using a conveyor, train, ship, etc. where it is washed to remove other component like dirt, sulphur, rocks, etc. and afterwards dried.

most historians agree that gabriel mouton, the vicar of st. paul’s church in lyons, france, is the “founding father” of the metric system. he proposed a decimal system of measurement in 1670. mouton based it on the length of one minute of arc of a great circle of the earth (now called a nautical mile, 1852 meters). he also proposed the swing-length of a pendulum with a frequency of one beat per second as the unit of length (about 25 cm). a pendulum beating with this length would have been fairly easy to produce, thus facilitating the widespread distribution of uniform standards. over the years, his work was revised, improved, and extended by a number of french scientists.

the political sponsor of weights and measures reform in the french revolutionary national assembly was the bishop of autun, better known as talleyrand. under his auspices, the french academy appointed several committees to carry out the work of developing a usable system of weights and measures for france. one of the committees recommended a decimalized measurement system based upon a length equal to one ten-millionth of the length of a quadrant of the earth’s meridian (i.e., one ten-millionth of the distance between the equator and the north pole).