A Yemeni student takes a final exam at a school in Sanaa, Yemen, on May 6, 2018. Nearly half a million students have dropped out of school since the civil war erupted in Yemen in 2015, bringing the total number of out-of-school children to 2 million, the UNICEF said in a statement released this March. The UNICEF also said in the statement that almost three quarters of public school teachers have not been paid their salaries in over a year, putting the education of an additional 4.5 million children at grave risk. (Xinhua/Mohammed Mohammed)