Coal is formed when peat is altered physically and chemically. This process is called coalification.. During coalification, peat undergoes several changes as a result of bacterial decay, compaction, heat, and time.
On January 9, 2011, ABC Family announced the show would return for its fourth season on March 26, 2011. On February 2, 2012, ABC Family renewed the series for a fifth season. On October 9, 2012, it was announced that the fifth season of The Secret Life of the American Teenager would be the final season. The series finale aired on June 3, 2013.
Secret Life of the American Teenager, centered on unexpected teen pregnancies and how the people involved deal with it, solidified the cable network as a major scripted player when it debuted in summer 2008, leading to future successes like Pretty Little Liars.