Parts of the teeth include: 1  Enamel: The hardest, white outer part of the tooth. Enamel is mostly made of calcium phosphate, a rock-hard mineral. 2  Dentine: A layer underlying the enamel. Dentine is made of living cells, which secrete a hard mineral substance.  Pulp: The softer, living inner structure of teeth.
Though they vary significantly, transportation costs accounted for 40% of the average overall cost of coal delivered at electric power plants in 2010. On average, nominal U.S. rail rates for shipping coal grew from $11.83 to $17.25 per short ton from 2001 to 2010.
However, booking a round trip flight can be a simpler process. You can compare round trip and one way flights by using our flight comparison. The average price for one way flights from Chicago to New York is $48. The average price for round trip flights from Chicago to New York is $80.e have collected flight cost data from across the web for travel from Chicago to New York, and have found the average flight price for this trip to be $87.