Iraqi pro-government forces fire an anti-tank cannon near al-Sejar village, north-east of Fallujah, on May 25, 2016, as they take part in a major assault to retake the city from the Islamic State (IS) group. Iraqi forces, consisting of special forces, soldiers, police, paramilitary-fighters and pro-government tribesmen, launched a major assault to retake Fallujah, the scene of deadly battles during the US occupation and one of the toughest targets yet in Baghdad's war on the Islamic State group. (Photo by Ahmad Al-Rubaye/AFP Photo)

Philippine Marines from the Naval Special Operations Group (NAVSOG) storm the beach to simulate an “extraction” of a kidnapped victim as they kick off a five-day amphibious military exercise at the Philippine Marines training center in Ternate, Cavite province, about 50 miles (80kms) south of Manila, Philippines Thursday, September 24, 2015. The naval exercise dubbed PAGSISIKAP 2015 is aimed at enhancing capability of their fleet and forces as well as to strengthen interoperability of the Marines. (Photo by Bullit Marquez/AP Photo)

Todd Bretl specializes in underwater photography, and is able to capture striking photos of aquatic life big and small. His photos of sharks are particularly striking; though he rarely faces hostility from the animals, he tries not to spend too much time looking through his viewfinder and many shots are framed by educated guesses and impeccable timing. What follows are photographs taken over the past several years on trips to the Bahamas and Isla Guadalupe, an island off the coast of the Baja California peninsula in Mexico. (Photo by Todd Bretl)

Students carry a female trainee who has fallen into a stupor during high intensity training at Tianjiao Special Guard/Security Consultant camp on the outskirts of Beijing December 1, 2013. Former Chinese soldier Chen Yongqing has big ambitions for his bodyguard training school Tianjiao, which he says is China's first professional academy to train former soldiers and others as personal security guards. Chen charges 500,000 yuan ($82,400) a year for each protector as China's rich and famous look to bolster their safety and sense of importance. (Photo by Jason Lee/Reuters)

An employee holds a plant with roots at the Plant Advanced Technologies (PAT) company greenhouse in Laronxe near Nancy, Eastern France, June 19, 2015. The farmers employed at the site in Laronxe are growing plants in a special way with a view to “milking” them for use in medicines, cosmetics and agrochemicals. Several major brands, including Germany's BASF and France's Chanel, have teamed up with Plant Advanced Technologies (PAT) in the hope of securing privileged access to the so-called “biomolecules” it extracts through the use of a patented technique. (Photo by Vincent Kessler/Reuters)

A couple wearing masks as a precaution against the spread of the new coronavirus walk on the Malecon seawall at sunset in Havana, Cuba, Monday, August 31, 2020. Cuban authorities will introduce new measures starting tomorrow Tuesday aimed at containing the spread of the coronavirus in Havana among others a curfew from 7 pm until 5 am and no one without special permission will be able to enter or leave the province. The new measures will last at least 15 days. (Photo by Ramon Espinosa/AP Photo)

Natalia Lage Rainha de Drums of the Escola de Samba Inocente de Belford Roxo during a presentation in the parade of the Special Group of Carnival in Rio de Janeiro at Avenida Marques de Sapucai, Sambadrome in Rio de Janeiro on April 21, 2021. The Carnival parades that take place in February were postponed to this month of April due to the high number of cases caused during the pandemic caused by COVID-19 (Coronavirus). (Photo by Thiago Ribeiro/AGIF via AFP Photo)

Handlers control the giant puppet MOCCO during a special training session in Takamori, Nagano prefecture, Friday, April 23, 2021. Tokyo 2020 organizers created about 10 meter-tall puppet to symbolize the spirit of the people from the regions affected by the 2011 earthquake and tsunami. The puppet will travel from Tohoku to Tokyo in May to be in place for the games scheduled to open in July. (Photo by Koji Ueda/AP Photo)