In this Wednesday, April 8, 2015 photo, Tim Hinrichs, of California, lifts his six-year-old son, Alex, to rub the nose of a bust of President Abraham Lincoln outside his tomb in Springfield, Ill. Local legend says rubbing the nose brings good luck. (Photo by Randy Squires/AP Photo)

A boy holds his father's rifle as they attend a protest by followers of the Houthi movement against the Saudi-led air strikes in Sanaa April 5, 2015. (Photo by Khaled Abdullah/Reuters)

An internally displaced Pakistani girl from a tribal area attends her daily lesson at a madrassa, a school for the study of Islam, on the outskirts of Islamabad, Pakistan, Monday, April 6, 2015. (Photo by B. K. Bangash/AP Photo)

Emma Day of Kearney, Neb. is swung around by the Missouri Western State mascot, Griffon, during an NCAA college baseball game between Missouri Western State and Nebraska-Kearney on Saturday, April 11, 2015, in St. Joseph, Mo. (Photo by Andrew Carpenean/AP Photo/St. Joseph News-Press)

A Yemeni child stands beside jerry cans full with water from a philanthropist-provided water tap in Sana?a, Yemen, April 7, 2015. According to reports, many Yemenis were affected by the airstrikes carried out by the Saudi-led coalition against Houthi rebels, as they are facing shortage of water and food. The Red Cross and Russia called for an urgent humanitarian ceasefire to allow medical aid to reach areas hit by the fighting and allow residents safe access to food and water. (Photo by Yahya Arhab/EPA)

A boy arrives to a driftwood soccer court, on the banks of the Rio Negro or Black River in Catalao community near Manaus, in Amazonas state April 4, 2015. Residents of Catalao, a village of houseboats, built a floating wooden soccer court, since the village field was flooded by the full Rio Negro. According to the Geological Survey of Brazil (CPRM), the full Rio Negro this year is expected to reach close to the record occurred in 2012, when the river reached the quota of 29.97 meters. (Photo by Bruno Kelly/Reuters)

Lynzi Jessen, 10, prepares to launch a paper airplane during Captain Ron Nielsen's “Fearless Flying” class at Sky Harbor International Airport in Phoenix, Arizona April 4, 2015. Jessen said she was nervous about a first-time flight she will have to take. (Photo by Nancy Wiechec/Reuters)

Children play at a public park in Dharavi, one of Asia's largest slums, in Mumbai April 8, 2015. (Photo by Danish Siddiqui/Reuters)

U.S. golfer Tiger Woods' son Charlie carries one of his father's clubs along the fourth hole during the par 3 event held ahead of the 2015 Masters at Augusta National Golf Course in Augusta, Georgia April 8, 2015. (Photo by Phil Noble/Reuters)

A foreign child plays in a tent on a sports field in Isipingo, south of Durban, April 9, 2015. Several hundred foreign nationals have sought refuge in the tents after xenophobia driven violence forced them to flee their homes. (Photo by Rogan Ward/Reuters)

A boy, who is a follower of the Houthi movement, carries his weapon during a protest against the Saudi-led air strikes in Sanaa April 10, 2015. (Photo by Mohamed al-Sayaghi/Reuters)

Young gymnasts practice pull-up on a bar at a gymnasium of a sports school in Jiaxing, Zhejiang province April 11, 2015. (Photo by William Hong/Reuters)

A girl sits in front of her mothr sleeping on the sidewalk in a street in Sanaa April 11, 2015. The humanitarian situation is witnessing a marked deterioration, a result of the war waged by the Saudi-led coalition forces According to media. (Photo by Mohamed al-Sayaghi/Reuters)

A boy plays in a playground on a hill called Merced, in an area which was affected by the Great Fire of Valparaiso last year, in Valparaiso April 11, 2015. This Sunday marks the first anniversary of the deadly wildfire that started on April 12, 2014 in the hills of Valparaiso. The fire destroyed thousands of predominantly low-income, wooden houses, leaving at least 15 people dead, according to officials. (Photo by Rodrigo Garrido/Reuters)

Children dressed in traditional Ukrainian clothing light candles during the Holy Fire ceremony on the eve of Orthodox Easter service in front of Volodymysky Cathedral in Kiev April 11, 2015. (Photo by Valentyn Ogirenko/Reuters)

Imran, a 3-year old boy from the Ukrainian Orthodox community living in Turkey, stands next to baskets of “paskha” cakes and eggs during the Easter service at the Orthodox Patriarchal Cathedral of St. George in Istanbul, April 12, 2015. (Photo by Murad Sezer/Reuters)

Residents inspect blood stains after what activists said was shelling by warplanes loyal to Syria's president Bashar Al-Assad on Saad Al-Ansari school in Aleppo's rebel-controlled Al-Mashad neighbourhood April 12, 2015. (Photo by Abdalrhman Ismail/Reuters)

A schoolgirl from the Karima Girls School dramatic society sheds a tear after they sang tribute songs for 22-year-old business management student Angela Nyokabi Githakwa, who previously went to the school and was killed in the Garissa University College attack and known to her friends as “Jojo”, during the funeral service in the village of Mutunguru, Kenya Friday, April 10, 2015. At one of the first funerals for the students killed in the Garissa attack, dozens of her friends and relatives gathered to say their final goodbyes at a funeral service held at the St. Joseph Catholic church, followed by a burial next to the banana plot at her parent's farm. (Photo by Ben Curtis/AP Photo)

Pax Zittergruen hugs his father, Nate Zittergruen, Sunday, April 5, 2015, during the Easter service at Lutheran Church of Hope in West Des Moines, Iowa. (Photo by Michael Zamora/AP Photo/The Des Moines Register)

A child reads a sign in favor of the U.S. repealing sanctions against Venezuela, before the arrival of Venezuela's President Nicolas Maduro to a monument honoring the victims of the 1989 U.S. invasion, in the Chorrillo neighborhood which saw the heaviest fighting during the invasion, in Panama City, Friday, April 10, 2015. (Photo by Ramon Espinosa/AP Photo)

A general view of atmosphere seen at the Twentieth Century Fox Premiere of “The Longest Ride” held at TCL Chinese Theatre on Monday, April 6, 2015, in Hollywood. (Photo by Eric Charbonneau/Invision for Twentieth Century Fox/AP Images)

A girl dressed as an angel walks home after marching in the annual Easter procession during traditional Semana Santa (Holy Week) festivities on April 5, 2015 in Ouro Preto, Brazil. Holy Week marks Easter celebrations for Catholics and Brazil holds the largest number of Catholics on the planet. Ouro Preto was a colonial mining town founded in the late 17th century and the Semana Santa tradition in Ouro Preto can be traced back to the 18th century Portuguese colonial period. (Photo by Mario Tama/Getty Images)

Luella Ries stands by a rabbit named Harris on Sunday, April 5, 2015, at the event for Easter in Bloomington, Minn. (Photo by Jeff Wheeler/AP Photo/Star Tribune)

A young Christian boy is frisked with a metal detector and has his bag searched to prevent against possible attacks, as he enters the compound of the Our Lady of Consolation Church, which was attacked with grenades by militants almost three years ago, in Garissa, Kenya Sunday, April 5, 2015. Easter Sunday's ceremony was laden with emotion for the several hundred members of Garissa's Christian minority, which is fearful following the recent attack on Garissa University College by al-Shabab, a Somalia-based Islamic extremist group, who singled out Christians for killing, though al-Shabab has a long record of killing Muslims over the years. (Photo by Ben Curtis/AP Photo)

Brianna Xin, 7, of Cary, NC does a cartwheel near cherry trees along the Tidal Basin on Tuesday April 07, 2015 in Washington, DC. (Photo by Matt McClain/The Washington Post)

Pakistani children browse through a pile of rotten oranges thrown by vendors at a fruit market in Lahore, Pakistan, Sunday, April 12, 2015. (Photo by Anjum Naveed/AP Photo)

A Tunisian boy holds a balloon reading in Arabic 'I love you Tunisia' during celebrations commemorating Martyrs Day, Tunis, Tunisia, 09 April 2015. Martyrs Day is marked annually 09 April to honor those who took part in wide spread protests 09 April 1938, after a popular leader of the Neo-Destour (New Constitution) Party was arrested, that were suppressed by French policemen killing at least 22 and injuring some 150 others. (Photo by Mohamed Messara/EPA)

Children are seen playing in a culvert in May Thirteen district of João Pessoa, Paraíba in Brazil on April 10, 2015. (Photo by Walter Paparazzo/G1)

Visitors look on painted eggs during Easter eggs (Pysanka) festival at St. Sophia's Cathedral in Kiev, Ukraine, 10 April 2015. Ukrainians will mark Orthodox Easter at 12 April, one week after Catholic believers. (Photo by Sergey Dolzhenko/EPA)

Girls are dressed as angels during the annual Easter procession during traditional Semana Santa (Holy Week) festivities on April 5, 2015 in Ouro Preto, Brazil. (Photo by Mario Tama/Getty Images)

Girls who survived what activists said was a ground-to-ground missile attack by forces of Syria's President Bashar al-Assad, hold hands at Aleppo's Bab al-Hadeed district April 7, 2015. (Photo by Abdalrhman Ismail/Reuters)

Catholics participate in the “Santo Entierro” (Holy Burial) procession during Good Friday, as part of Holy Week celebrations in Guatemala City, on April 3, 2015. Christians around the world are marking the Holy Week, commemorating the crucifixion of Jesus Christ, leading up to his resurrection on Easter. (Photo by Johan Ordonez/AFP Photo)

Pakistani children play near the Ravi river in Lahore on April 6, 2015. (Photo by Arif Ali/AFP Photo)