President Barack Obama watches as Joey Hudy (L), 14, from Phoenix, Arizona pumps the Extreme Marshmallow Cannon he invented, while touring student science fair projects on exhibit in the State Dining Room at the White House February 7, 2012 in Washington, DC. Obama hosted the second White House Science Fair celebrating the student winners of science, technology, engineering and math (STEM) competitions from across the country. (Photo by Molly Riley-Pool/Getty Images)

A fairy tale and movie-themed gingerbread house creation, featuring a reindeer, made by pastry students of the San Ysidro Adult School Culinary Arts program is pictured during their 9th annual gingerbread house competition in San Ysidro, California December 9, 2014. The students' voting results will be delivered back to their class but the official judging will be performed by chefs and culinary experts during the 9th annual event. (Photo by Mike Blake/Reuters)

A mother prays for success for her child in the college entrance examinations at a Buddhist temple in Seoul, South Korea, November 12, 2015. About 630,000 students on Thursday sat for the annual exams that could lead them to one of the country's top universities. In South Korea, there is no higher achievement than to be accepted by a prestigious university. As a result, many students prepare for these entrance exams from an early age, often studying up to 16 hours a day for years to take this test. (Photo by Kim Hong-Ji/Reuters)

In this photo submitted by the Washington Post tilted “The Moment Time Stopped”, survivors piled bodies of the dead outside for weeks after earthquake on January 14, 2010 in Port-au-Prince, Haiti. The 7.0 magnitude earthquake struck in 2010, and the Haitian government has said more than 300,000 people were killed. The exact toll is unknown because there was no systematic effort to count bodies among the chaos and destruction. (Photo by Carol Guzy/AP Photo/The Washington Post)

A student activist is detained during a silent protest after Thailand's election commission filed charges against a group for posting “foul and strong” comments online criticising a military-backed draft constitution, in Bangkok, Thailand April 27, 2016. (Photo by Jorge Silva/Reuters)

A student is assisted by teachers after she fell ill while marching in a parade celebrating Saint Peter's day in Lima, Peru, Monday, June 29, 2015. During the feast day of the Catholic saint, who is the patron saint of fishermen, coastal communities pay homage to St. Peter, whose statue is paraded to the sea and petitions are made to keep their vessels and all who work on them safe. (Photo by Rodrigo Abd/AP Photo)

An Indian student warms up during the 44th Samartha Summer Sports Coaching Camp organized by Shree Samarth Vyayam Mandir in Mumbai, India, 25 April 2018. Mallakhamba arose in the western state of Maharashtra centuries ago. It was originally practiced by wrestlers and soldiers as a strength training exercise. (Photo by Divyakant Solanki/EPA/EFE)

In this Thursday, June 14, 2018, file photo, students wear virtual reality goggles during a science class at Pyongyang Teachers' University, a teacher training college, in Pyongyang, North Korea. (Photo by Dita Alangkara/AP Photo)