Medic James E. Callahan of Pittsfield, Mass., gives mouth-to-mouth resuscitation to a dying soldier in war zone D, about 50 miles northeast of Saigon, June 17, 1967. Thirty-one men of the 1st Infantry Division were reported killed in the guerrilla ambush, with more than 100 wounded. (Photo by Henri Huet/AP Photo)

Milena Jami whips her llama to win the first place in the a race for children of ages seven and eight at the Llanganates National Park, Ecuador, Saturday, February 8, 2020. Wooly llamas, an animal emblematic of the Andean mountains in South America, become the star for a day each year when Ecuadoreans dress up their prized animals for children to ride them in 500-meter races. (Photo by Dolores Ochoa/AP Photo)

Models wait backstage before the Heaven Gaia Autumn/Winter 2021 collection show by Xiong Ying during China Fashion Week in Beijing, China on March 25, 2021. (Photo by Tingshu Wang/Reuters)

A boy dressed as Lord Krishna is pictured while Hindu devotees march on the streets to celebrate Janmashtami festival, which marks the birth anniversary of Lord Krishna, in Dhaka, August 14, 2017. (Photo by Mohammad Ponir Hossain/Reuters)

Enthusiasts gathered at Cad East in Snowdonia National Park, England to take pictures of F-15 Eagle fighters as they completed the Mach Loop, November 2017. (Photo by Caters News Agency)

A man wears a busho mask and a costume made of sheep pelt while climbing up a ladder outside a barn in Mohacs, Hungary, 20 February 2020, on the first day of carnival. The traditional Busho carnival, which marks the end of winter, dates back to the 16th century. According to local legend, members of an ethnic South Slavic group living in Mohacs at the time dressed up in similar costumes and wore wooden masks to scare away Ottoman invaders, who mistook them for demons. (Photo by Tamas Soki/EPA/EFE)

A train attendant wearing a protective face mask stands on a train to Wuhan, at the railway station in Beijing, China, 29 March 2020. Wuhan, the epicenter of the coronavirus outbreak, partly lifted the lockdown allowing people to enter the city after more than two months. Chinese authorities eased the quarantine measures as cases of Covid-19 across China have plummeted, according to Chinese government figures. (Photo by Roman Pilipey/EPA/EFE)

A citizen wearing protective suit shops at a market in Santiago, Chile, April 16, 2020 Chile has taken stringent measures to contain the virus, including imposing a night time curfew, suspending classes, closing non-essential businesses, and mandating the use of face masks on all public transit. (Photo by Jorge Villegas/Xinhua News Agency)