Britain's Catherine, the Duchess of Cambridge greets patient Rafael Chana, 4, during a visit to Great Ormond Street Hospital to officially open the Mittal Children's Medical Centre, in London, January 17, 2018. REUTERS/Frank

A man selects deli from a partially empty refrigerator at a supermarket in San Cristobal, Venezuela January 16, 2018. REUTERS/Carlos Eduardo Ramirez

U.S. President Donald Trump speaks during an interview with Reuters at the White House in Washington, U.S., January 17, 2018. REUTERS/Kevin Lamarque

Victim Nicole Walker, a former gymnast, speaks during a sentencing hearing for Larry Nassar, a former team USA Gymnastics doctor who pleaded guilty in November 2017 to sexual assault charges, in Lansing, Michigan, U.S., January 17, 2018. REUTERS/Brendan McDermid

Former student leader Joshua Wong reacts outside High Court before receiving his sentence in Hong Kong, China January 17, 2018. REUTERS/Bobby Yip

Figure Skating - ISU European Championships 2018 - Opening Ceremony - Moscow, Russia - January 17, 2018 - Son of Russian former figure skater Evgeni Plushenko, Alexander performs. REUTERS/Grigory Dukor

A Palestinian girl looks through a plastic sheet as raindrops are seen, outside her family's house in Al-Shati refugee camp in Gaza City January 17, 2018. REUTERS/Mohammed Salem

A man rides a horse through flames during the annual "Luminarias" celebration on the eve of Saint Anthony's day, Spain's patron saint of animals, in the village of San Bartolome de Pinares, northwest of Madrid, Spain, January 16, 2018. Picture taken January 16, 2018. REUTERS/Juan Medina

U.S. Senator Lindsey Graham (R-SC) speaks to reporters as he arrives for the weekly Republican party caucus luncheon at the U.S. Capitol in Washington, U.S., January 17, 2018. REUTERS/Jonathan Ernst

A person enter in sauna on the peak of Mount Lagazuoi in Cortina D'Ampezzo, Italy January 16, 2018. Picture taken January 16, 2018. REUTERS/Stefano Rellandini

Dakar Rally - 2018 Peru-Bolivia-Argentina Dakar rally - 40th Dakar Edition stage eleven, Belen to Chilecito- January 17, 2018. Nasser Al-Attiyah of Qatar and Matthieu Baumel of France drive their Toyota. REUTERS/Andres Stapff

Residents of the zoned ZAD (Deferred Development Zone) react after the French government's official announcement to abandon the Grand Ouest Airport (AGO) project in Notre-Dame-des-Landes, near Nantes, France, January 17, 2018. REUTERS/Stephane Mahe

Peruvian shamans perform a ritual prior to the arrival of Pope Francis to Peru, at Pescadores beach in Chorrillos, Lima, Peru, January 17, 2018. REUTERS/Guadalupe Pardo

People gather to protest against plans to further restrict abortion laws in Krakow, Poland January 17, 2018. Jakub Porzycki/Agencja Gazeta via Reuters Banner reads "Women's rights - women's business" .

Tennis - Australian Open - Rod Laver Arena, Melbourne, Australia, January 17, 2018. Rafael Nadal of Spain serves against Leonardo Mayer of Argentina. REUTERS/Thomas Peter

A worker closes the security shutter of a window display at a shoes store in downtown Caracas, Venezuela January 16, 2018. Picture taken January 16, 2018. REUTERS/Marco Bello

Three-year-old dog "Vullet" poses for a portrait before being blessed by a priest outside San Anton Church in Madrid, Spain, January 17, 2018. Hundreds of pet owners bring their animals to be blessed every year on the day of Saint Anthony, Spain's saint patron of animals. REUTERS/Susana Vera

U.S. President Donald Trump confers with White House Communications Director Hope Hicks (L) as White House Press Secretary Sarah Sanders (R) listens during an interview with Reuters at the White House in Washington, U.S., January 17, 2018. REUTERS/Kevin Lamarque

A flock of sheep is blessed by a priest on the day of Saint Anthony, Spain's patron saint of animals, in Muro, in the island of Mallorca, Spain January 17, 2018. REUTERS/Enrique Calvo

Waves crash on the lighthouse of "La Isla del Mouro" in the port town of Santander, Spain, January 17, 2018. REUTERS / Eloy Alonso

A man and dog walk in the falling snow in Rockland Lake State Park near the Hudson River in Clarkstown, New York, U.S., January 17, 2018. REUTERS/Mike Segar

SEED Solutions' platform robot SEED-Noid picks up tea leaf from a tea tree during its demonstration at Robot Development & Application Expo in Tokyo, Japan January 17, 2018. REUTERS/Kim Kyung-Hoon