Complex sentence: Liberia's economic and political stability was recently threatened by a deadly Ebola virus epidemic which originated in Guinea in December 2013 and entered Liberia in March 2014, but the outbreak officially ended on May 8,2015, after 42 days with no new cases.
Split into simpler sentences: Liberia's economic and political stability has recently been threatened by a deadly Ebola virus epidemic which originated in Guinea in December 2013 and entered Liberia in March 2014. The outbreak was declared over on May 8,2015, after 42 days with no new cases.