Nargis Yadav enters the world to the sound of clicking cameras. Born to a farmer couple in populous northern India, the baby girl is attracting media attention as one of the world's symbolic "seven billionth babies." The world population reached seven billion on Monday (October 31). 　　United Nations Secretary General Ban Ki-moon marked the milestone, warning that the newborns now inhabit a difficult world. BAN KI-MOON, (UNITED NATIONS SECRETARY-GENERAL) : "Famine in the Horn of Africa, fighting in Syria and elsewhere. Protests against growing economic inequality from Wall Street to Main Street. Rising public anger. 　　Loss of faith in governments and public institutions to do the right thing. Our world is one of terrible contradictions."The U.N. is not designating any specific baby as the world's seventh billionth human. Instead, a number of babies born around the world on Monday are being certified as "one of the seven billionth babies." (Katharine Jackson/ Reuters)