FTR is a British rapid-transit bus system, currently in operation in Leeds, Luton and Swansea.irst Group has introduced the system, using Wright StreetCar articulated buses in conjunction with infrastructure upgrades by local authorities. The vehicles have been branded as the future of travel, the operators claiming that ftr is textspeak for the word future.
Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such as coral, forams and molluscs. Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate (CaCO3).
Commodity: Limestone, a sedimentary rock that is dominantly composed of the calcium-bearing carbonate minerals calcite and dolomite. Calcite is chemically calcium carbonate (formula CaCO3). Dolomite is chemically calcium-magnesium carbonate (formula CaMg(CO3)2). Economic Importance: Limestone is used to make a variety of products that are essential to the modern way of life (see Uses section below).