An employee of the National Park Service takes a selfie with President Barack Obama, left, in the background meeting with the crowd after a tour of Everglades National Park on Earth Day, Wednesday, April 22, 2015, in Florida. Obama used the visit to warn of the damage that climate change is already inflicting on the nation's environmental treasures. (Photo by Lynne Sladky/AP Photo)

An instructor (C) adjusts the posture of students of flight attendant major during a training session at Anhui Foreign Languages University, in Hefei, Anhui province, China, May 25, 2015. (Photo by Reuters/China Daily)

New Orleans police officers try to keep their heads down as they move in on a Black Panther headquarters during an exchange of gunfire in New Orleans on September 15, 1970. The shootout occurred as police moved in to make arrests on Tuesday morning following a series of incidents. (Photo by Jack Thornell/AP Photo)

Villagers riding a rickshaw maneuver along an overflowing dam at the border between Cavite province and Las Pinas city, in Las Pinas, Philippines, 25 October 2020. According to Philippine Atmospheric Geophysical and Astronomical Services Administration (PAGASA), Typhoon Molave will make landfall in the evening of 25 October in southern Luzon island. An alert was issued to residents for possible floods and landslides. (Photo by Francis R Malasig/EPA/EFE)

A motorcycle carrying a pig crosses a flooded road in Albay province, central Philippines due to Typhoon Vamco on Thursday, November 12, 2020. (Photo by John Michael Magdasoc/AP Photo)

Young women pose for photos in a Christmas-themed tunnel lit-up with decorations outside a shopping mall in Bangkok on December 4, 2020. (Photo by Mladen Antonov/AFP Photo)

A man prepares to tie a black ribbon next to a makeshift memorial during a prayer ceremony for the victims of the 2004 tsunami on the 16th anniversary of the disaster, at Marina Beach in Chennai, India, December 26, 2020. (Photo by P. Ravikumar/Reuters)

Participants approach a law enforcement officer with open arms during an opposition demonstration to protest against police violence and to reject the presidential election results near the Government House in Independence Square in Minsk, Belarus on August 14, 2020. (Photo by Vasily Fedosenko/Reuters)