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).
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate (CaCO 3). Glass making, in some circumstances, uses limestone. 2  It is added to toothpaste, paper, plastics, paint, tiles, and other materials as both white pigment and a cheap filler. 3  It can suppress methane explosions in underground coal mines. 4  Purified, it is added to bread and cereals as a source of calcium.