A young girl who is a member of the RAF cadets walks between gravestones at Tyne Cot World War One cemetery in Zonnebeke, Belgium. Tyne Cot is now the largest Commonwealth war cemetery in the world in terms of burials. There are 11,956 Commonwealth servicemen of the First World War buried or commemorated in the cemetery, 8,369 of those burials are unidentified. Other special memorials commemorate 20 casualties whose graves were destroyed by shell fire and there are 4 German burials, 3 being unidentified. Nov. 12, 2013 (AP Photo/Virginia Mayo)
A girl pulls water from a well in the home of Ahmed al-Kawkabani, leader of the southern resistance unit in Hodeida, in al-Khoukha, Yemen. Feb. 12, 2018 (AP Photo/Nariman El-Mofty, File)
Hannah Shraim, 17, left, fixes a scarf around Lana Algamil, 5, after the little girl asked Hannah if she could try one on before evening prayers at the Shraim family home in Germantown, Md. May 6, 2016 (AP Photo/Jacquelyn Martin, File)
Morgan Hurd practices on the balance beam during a training session at the U.S. Gymnastics Championship. Aug. 15, 2018 (AP Photo/Elise Amendola, File)
Janet Jotham braids the hair of her daughter Lucia Jotham, 8, during a visit to see her two children living at the Kabanga Protectorate Center in Kabanga, Tanzania. Aug. 27, 2012 (AP Photo/Jacquelyn Martin)
Students rally in front of the White House in Washington. Students walked out of school to protest gun violence in the biggest demonstration yet of the student activism that has emerged in response to a massacre of 17 people at Florida's Marjory Stoneman Douglas High School. March 14, 2018 (AP Photo/Carolyn Kaster, File)
Nysa Loudon, 11, swings in the neighborhood park ravaged by Hurricane Katrina near her home in Gentilly area of New Orleans, La., 2006. She wears her angel wings for the Krewe of Druex Mardi Gras parade that will march through Gentilly. Keeping a tradition alive, the krewe gathered for the 34th year in a row to parade through the hurricane ravaged neighborhood. Feb. 25, 2006 (AP Photo/Carolyn Kaster, File)
A young clown rides in the back of a car following a procession to the Basilica of Our Lady of Guadalupe in Mexico City. Hundreds belonging to various clown associations made their annual pilgrimage to the Basilica to pay their respects to the Virgin of Guadalupe, Mexico's patron saint. Dec. 14, 2015 (AP Photo/Rebecca Blackwell)
Schoolgirls walk through the rocky yard of Bethesda Evangelical School during a break in class, in Canaan, Haiti. June 24, 2015 (AP Photo/Rebecca Blackwell, File)
Samantha Bischoff, left, compliments Hannah Shraim on her prom dress during Northwest High School's senior prom at the Fillmore Theater in Silver Spring, Md. Senior class president and an observant Muslim, Shraim prays five times a day and hopes to become an advocate for Muslims in the United States. May 13, 2016 (AP Photo/Jacquelyn Martin, File)
Rohingya Muslim girls carry water pots in Kutupalong refugee camp in Bangladesh. Nov. 19, 2017 (AP Photo/Wong Maye-E, File)
Nurya Temam, center front, a 10th grade student at Northwest School, cheers with other students who walked out of classes in Seattle as they protest the election of Donald Trump as president. Nov. 14, 2016 (AP Photo/Elaine Thompson, File)
Luana poses for photos on her roller skates at her home in Merlo, Argentina. Luana says that when one of the girls asked her why she had a penis, a friend jumped in. "She's transsexual," the child explained, nonchalantly. That level of comfort is no doubt in part because Luana herself appears so at ease. In 2013, she became the youngest person to take advantage of a progressive Argentine law that allows people to identify their own gender for legal purposes. Sept. 29, 2015 (AP Photo/Natacha Pisarenko, File)
A Pakistani girl lines up among boys for their morning assembly where they sing the national anthem at a school in Islamabad, Pakistan. Oct. 11, 2013 (AP Photo/Anja Niedringhaus, File)
An Afghan girl tries to peer through the holes of her burqa as she plays with other children in the old town of Kabul, Afghanistan. April 7, 2013 (AP Photo/Anja Niedringhaus, File)
A young girl in her colorful dress reaches out to greet a Pakistani policeman securing the road outside Kainat Riaz's home in Mingora, Swat Valley, Pakistan. Nov. 15, 2012 ( AP Photo/Anja Niedringhaus, File)
Baby Seibureh, 17, and Claude Seibureh, 48, of Freetown, were married during the Ebola crisis. Because of her small stature, Baby needed a cesarean section to safely give birth to their son, Joseph. While child marriage is a critical issue in both crisis and stable contexts, child marriage is rising at alarming rates in humanitarian settings. 2016 (Stephanie Sinclair/Too Young to Wed via AP)
Bedouin children run after a pick up truck in Abu Galoum, South Sinai, Egypt. Jan. 2, 2016 (AP Photo/Nariman El-Mofty, File)
From left, Ranjeda, 9, Rumana, 10, Minajan, 10 and Wisma Bi Bi, 12, smile at each other while waiting in their classroom in Chakmarkul refugee camp, Bangladesh. Amid the misery and mud of Bangladesh's refugee camps, Rohingya girls have found small moments of joy by adorning themselves with flowery headbands and elaborately-drawn makeup. June 27, 2018 (AP Photo/Wong Maye-E, File)
Hagar Yahia holds her daughter Awsaf, a thin 5-year-old who is getting no more than 800 calories a day from bread and tea, half the normal amount for a girl her age, in Abyan, Yemen. Yahia, a mother of eight breaks down in tears talking about her family's deprivation. Late last year, as fighting closed in on Hayis, they fled more than 200 miles, eventually ending up in the village of Red Star on the Arabian Sea coast in the south. Ever since, they've struggled to find enough food. Feb. 9, 2018 (AP Photo/Nariman El-Mofty, FILE)
Students gather to grieve during a vigil at Pine Trails Park for the victims of a shooting at Marjory Stoneman Douglas High School, in Parkland, Fla.. Feb. 15, 2018 (AP Photo/Brynn Anderson, File)
Isaiah Rivera, 6, center, and Jonathan Medina, 11, cool off at an open fire hydrant in the East Village neighborhood of Manhattan. Vanity Mendez, 11 (AP Photo/Mary Altaffer, File)
Luis Varela, 17, left, Gabby Reynolds, 18, and Mariah Perry, 15, all of Birmingham, Ala., enjoy the festivities and music during a Day of the Dead celebration, in Birmingham, Ala. Nov. 2, 2016 (AP Photo/Brynn Anderson, File)
Ansa Khan and her sister's combs hang on the mud wall of her house in Mardan, Pakistan. June 27, 2018 (AP Photo/Saba Rehman)
Girls turning 15 pose in their gowns for photos inside a pink limousine before their debutante ball, organized by the Peacemaker Police Unit program in the Mangueira favela, or shantytown, in Rio de Janeiro, Brazil. The debutante ball marks girls' transition from childhood to adulthood and is common in Brazil and other Latin American countries. Nov. 8, 2012 (AP Photo/Silvia Izquierdo, File)
After a rally in front of the White House, students march up Pennsylvania Avenue toward Capitol Hill in Washington. Students walked out of school to protest gun violence in the biggest demonstration yet of the student activism that has emerged in response to last month's massacre of 17 people at Florida's Marjory Stoneman Douglas High School. March 14, 2018 (AP Photo/Carolyn Kaster, File)