In this photo taken April 14, 2015, Lera, 11, plays with a teacher during an art class in the Center for Children with Disabilities, Rodyna, (Family) in Kiev, Ukraine. International rights group, Disability Rights International said in a report released Thursday April 16, 2015, that growing numbers of disabled children in Ukraine are being condemned to life in orphanages and institutions blighted by neglect and abuse. (Photo by Efrem Lukatsky/AP Photo)

Hayden Lewis, of Norwalk, Conn., cousin of Sandy Hook School shooting victim Jesse Lewis, stands with family during a news conference at the Legislative Office Building, Monday, April 13, 2015, in Hartford, Conn. (Photo by Jessica Hill/AP Photo)

In this Tuesday, April 14, 2015 photo, Sudanese children play on the Nile River bank, in Khartoum, Sudan. (Photo by Mosa'ab Elshamy/AP Photo)

An Afghan refugee child walks near to his home in Kabul, Afghanistan, Thursday, April 16, 2015. (Photo by Allauddin Khan/AP Photo)

A boy watches as people and security forces gather at the scene of a car bomb explosion in Habibya in eastern Baghdad, Iraq, Friday, April 17, 2015. (Photo by Karim Kadim/AP Photo)

In this picture taken on Tuesday, April 14, 2015, a Sudanese boy rides a bicycle in Izba, an impoverished neighborhood on the outskirts of Khartoum, Sudan. Izba is one sign of how the constant internal wars, under Sudan's President Omar al-Bashir, have shaped, Khartoum. Before al-Bashir came to power, Izba was home to a community of Arab tribesmen who had settled here to be close to the capital. But through the 1990s and 2000s, it swelled with Sudanese fleeing war zones around the country. Now 70,000 people live crammed into Izba, an area of about a square mile. (Photo by Mosa'ab Elshamy/AP Photo)

A Bangladeshi child watches from behind soldiers of Bangladeshi Rapid Action Battalion a rally to celebrate the first day of the Bangla New Year in Dhaka, Bangladesh, Tuesday, April 14, 2015. (Photo by A. M. Ahad/AP Photo)

Melanie Vela, 7, wears clothing inspired by Selena during the second day of Fiesta de la Flor: A celebration of the Life & Legacy of Selena on Saturday, April 18, 2015, at North Bayfront Park in Corpus Christi, Texas. (Photo by Gabe Hernandez/Corpus Christi Caller-Times via AP Photo)

Two unidentified young boys, Talibe students, walk in a field littered with garbage, holding the buckets from which they ate a lunch of rice and fish in Guediawaye, a suburb on the outskirts of of Dakar, Senegal, Monday, April 20, 2015. They need to find more food before returning to school so they don't get beaten. Human Rights Watch and a coalition of 40 organizations in Senegal are calling on the government and police to enforce laws adopted nearly a decade ago that prohibit forcing children to beg. The groups issued a report Monday that said more than 30,000 Muslim boys who are sent to Quranic schools in Dakar region are exploited by teachers and forced to beg for food and money. (Photo by Jane Hahn/AP Photo)

In this picture taken on Tuesday, April 14, 2015, Sudanese boys play on a makeshift swing outside their school in Izba, an impoverished neighborhood on the outskirts of Khartoum, Sudan. Izba is one of Khartoum's densely populated districts only 12 kilometers from the center of the Sudanese capital. (Photo by Mosa'ab Elshamy/AP Photo)

A Yemeni boy holding a weapon, poses for a picture during a demonstration against an arms embargo imposed by the U.N. Security Council on Houthi leaders, in Sanaa, Yemen, Thursday, April 16, 2015. (Photo by Hani Mohammed/AP Photo)

Jane, the sister of Boston Marathon bombing victim Martin Richard, sits on a new bench with the words “Keep Running Boston” and “Boston Strong” on it outside the fire station on Boylston Street on the second anniversary of the Boston Marathon bombings in Boston, Massachusetts April 15, 2015. (Photo by Brian Snyder/Reuters)

A Zimbabwean child sits between bales at the Boka Tobacco Auction Floors in Harare, Zimbabwe April 14, 2015. (Photo by Philimon Bulawayo/Reuters)

An Afghan boy jumps into a muddy body of water as he goes for a swim with his friends on the outskirts of Jalalabad April 16, 2015. (Photo by Reuters/Parwiz)

A boy stands among followers of the Houthi group during a demonstration against an arms embargo imposed by the U.N. Security Council on the group in Sanaa April 16, 2015. (Photo by Mohamed al-Sayaghi/Reuters)

Jamaican Olympic gold medallist Usain Bolt (C) runs with youths at Mangueira slum Olympic center, ahead of the “Mano a Mano” challenge, a 100-meter race which will be held on this Sunday, in Rio de Janeiro April 16, 2015. (Photo by Ricardo Moraes/Reuters)

Yemeni children eat at a temporary shelter after fleeing violence with their families in Yemen, at the port town Bosasso in Somalia's Puntland April 17, 2015. (Photo by Feisal Omar/Reuters)

A Palestinian boy attends a rally marking Palestinian Prisoners' Day organised by Islamic Jihad movement in Khan Younis in the southern Gaza Strip April 17, 2015. (Photo by Ibraheem Abu Mustafa/Reuters)

A child plays with a balloon inside a compound for Syrian Refugees in Sidon, south Lebanon April 17, 2015. (Photo by Ali Hashisho/Reuters)

A boy plays on a damaged bicycle inside a compound for Syrian Refugees in Sidon, south Lebanon April 17, 2015. (Photo by Ali Hashisho/Reuters)

A boy eats while playing in a basket with other boys inside a compound for Syrian Refugees in Sidon, south Lebanon April 17, 2015. (Photo by Ali Hashisho/Reuters)

Children gesture as they ride on an elephant outside a temple in the western Indian city of Ahmedabad April 20, 2015. (Photo by Amit Dave/Reuters)

Medical staff carry James Dorbor, 8, suspected of having Ebola, into a treatment facility in Monrovia, Liberia, September 5, 2014. (Photo by Daniel Berehulak/Reuters/The New York Times)

A Syrian boy stands in the entrance of his tent as he watches the visiting of the United Nations High Commissioner for Refugees (UNHCR) Antonio Guterres, during his visit to an informal seaside camp, in the southern costal town of Sarafand, Lebanon, Tuesday, April 14, 2015. (Photo by Mohammed Zaatari/AP Photo)

A child queues for food at a temporary refugee camp for foreign nationals, east of Johannesburg, South Africa, Monday, April 20, 2015. A total of seven people have died in attacks on immigrants in South Africa in the past week bringing the South African president to postpone a key ceremony, his office said Monday. The anti-immigrant violence has been in specific areas of Durban and Johannesburg. Six people died in attacks in the coastal city of Durban, where looters broke into shops owned by immigrants, police said. The violence has since subsided. (Photo by Themba Hadebe/AP Photo)

In this Thursday, March 12, 2015 photo, first-graders learn keyboarding skills at Bayview Elementary School in San Pablo, Calif. Schools around the country are teaching students as young as 6, basic typing and other keyboarding skills. The Common Core education standards adopted by a majority of states call for students to be able to use technology to research, write and give oral presentations, but the imperative for educators arrived this month with the introduction of standardized tests that are taken on computers instead of with paper and pencils. (Photo by Eric Risberg/AP Photo)

Valerie Gonzalez, 5, a student at The Growing Place preschool in Coral Gables, Fla., smiles as she tries on a tactical vest and helmet during an open house event at Coast Guard Air Station Miami, Friday, April 17, 2015, in Opa-Locka. About 1,500 students from Miami-Dade and Broward County schools attended the event where they could climb aboard various aircraft and vessels used by the Coast Guard and other law enforcement agencies. (Photo by Wilfredo Lee/AP Photo)

Young girls perform during the opening ceremony of the Yangon Mayor water festival in Yangon, Myanmar, 13 April 2015. The annual water festival is celebrated with large groups of people congregating to celebrate by splashing water and throwing powder at each others faces as a symbolic sign of cleansing and washing away the sins from the old year to mark the traditional New Year in countries such as Myanmar, Thailand, Laos and Cambodia. This year Myanmar Thingyan water festival falls on 13 April and ends on 16 April. (Photo by Nyein Chan Naing/EPA)

A visitor holds up her toy bunny to the aquarium glass in front of Aurora the Russian polar bear at the Sao Paulo Aquarium in Sao Paulo, Brazil, Thursday, April 16, 2015. (Photo by Andre Penner/AP Photo)

Young gymnasts practice at a gymnasium of a sports school in Jiaxing, Zhejiang province, on April 17, 2015. (Photo by Reuters/Stringer)

A Syrian refugee woman begs with her children on the street in the Beyoglu district of Istanbul on April 17, 2015. (Photo by Bulent Kilic/AFP Photo)

A Palestinian child throws a stone towards Israeli forces during clashes between Palestinian protestors and security forces following a demonstration in support of Palestinian men imprisoned in Israeli jails and against the expropriation of land by Israel, on April 17, 2015 in the village of Kfar Qaddum, near Nablus in the occupied West Bank. (Photo by Jaafar Ashtiyeh/AFP Photo)

Street children sleep on a discarded mattress on a center island near a road crossing in Manila on April 12, 2015. The world marks International Day for Street Children on April 12 to campaign for the rights of impoverished children. (Photo by Jay Directo/AFP Photo)

Children play on April 13, 2015 at a refugee boarding facility run by the UN High Commission for Refugees at Obock, a small port town in Djibouti located on the northern shore of the Gulf of Tadjoura, where it opens out into the Gulf of Aden. (Photo by Tony Karumba/AFP Photo)

Tatyana Frost, right, leads a group of moms in an exercise class at Way 2 Dance Studio in Brandon, Fla., Tuesday, April 14, 2015. On the left is Julie Ann Padilla and 16 month old Josiah in the middle is Amber Riley with Amyia Kate Riley, 11 months. (Photo by Skip O'Rourke/The Tampa Bay Times via AP Photo)

Young ballet dancer Himika Tamamoto,7, stretches her leg during auditions, as boys and girls ages 6 to 7 year old try out for The School of American Ballet Winter Term, at the P.S. 124 Yung Wing school in New York's Chinatown on April 16, 2015. (Photo by Timothy A. Clary/AFP Photo)

Yemeni refugee children stand on April 12, 2015 at a boarding fracility run by the UN High Commission for Refugees in Obock, a small port in Djibouti on the northern shore of the Gulf of Tadjoura, where it opens out into the Gulf of Aden. (Photo by Tony Karumba/AFP Photo)

A Papuan girl comforts her crying young sister in Wanam village, Papua province, Indonesia, Wednesday, April 15, 2015. (Photo by Dita Alangkara/AP Photo)