The top routes that United Airlines flies are: 1  CLT to ORD with 3,755 flights per month. 2  CLT to IAH with 3,511 flights every month. 3  DFW to ORD with 3,486 flights every month.  DFW to EWR with 3,268 flights every 1  month. PHL to ORD with 3,238 flights every month.
The first of the three rock types to form on Earth were the igneous rocks; formed from the cooling and solidification of magma, as the Earth was at one time completely molten. â¦. 4 people found this useful.
Examples of this rock type include gneiss and marble. Igneous. Igneous rocks are formed when magma (molten rock deep within the earth) cools and hardens. Sometimes the magma cools inside the earth, and other times it erupts onto the surface from volcanoes (in this case, it is called lava).xamples of this rock type include gneiss and marble. Igneous. Igneous rocks are formed when magma (molten rock deep within the earth) cools and hardens. Sometimes the magma cools inside the earth, and other times it erupts onto the surface from volcanoes (in this case, it is called lava).