Prospective flight attendants listen to their instructor during an etiquette training course at Indigo Airlines' Ifly training centre in Gurgaon on the outskirts of New Delhi November 18, 2014. (Photo by Adnan Abidi/Reuters)

Three Boeing 737 fuselages lie on an embankment on the Clark Fork River after a BNSF Railway Co train derailed Thursday near Rivulet, Montana in this picture taken July 4, 2014. A train derailment in Montana this week damaged a shipment of jetliner fuselages and other large parts on its way to Boeing Co factories in Washington state from Spirit Aerosystems, Boeing said on Saturday. (Photo by Kyle Massick/Reuters)

Members of the media touch a moving model of a Tyrannosaurus, which uses a dinosaur-type human-operated mechanical suit called “Dino-Techne” by Japanese firm On-Art, during a media preview of the Dinoa Live Exhibition / Amazing Dinosaur Art Exhibition in the Shinjuku district of Tokyo on December 10, 2020. (Photo by Philip Fong/AFP Photo)

People wearing face masks walk through Ginza area on December 27, 2020 in Tokyo, Japan. Japan announced it will close its borders to non-resident foreign nationals from tomorrow until the end of January after two people were discovered to be infected with a new strain of Covid-19 coronavirus that has begun spreading around the world. The country is also grappling with a surge in coronavirus infections, with Tokyo reporting 708 cases today. To date, Japan has recorded 218,453 infections, 3,052 deaths and 3,052 recoveries from the virus. (Photo by Yuichi Yamazaki/Getty Images)

Women dressed in kimonos pose for a selfie photograph at a deserted torii path Fushimi Inari Taish shrine on January 18, 2021 in Kyoto, Japan. Kyoto, along with a Osaka and several other prefectures, was brought under a state of emergency last week by the Japanese government as they grapple to contain the third, and most virulent, wave of Covd-19 coronavirus to hit the country. (Photo by Buddhika Weerasinghe/Getty Images)

A man stands in front of a poster created by artist Tomoko Konoike, one of 20 posters officially selected for the Tokyo Olympics and Paralympics, at the Museum of Contemporary Art Tokyo Monday, January 6, 2020. The official posters are out for this year's Tokyo Olympics and Paralympics. The 20 posters have been created by 19 artists in fields ranging from painting, graphic design, and photography. Calligraphy and Japanese manga are also represented. (Photo by Jae C. Hong/AP Photo)

A tourist pauses for photos with her mask on at Sensoji Temple Thursday, January 30, 2020, in Tokyo. The country began evacuating Japanese citizens on Wednesday from the Chinese city Wuhan hardest-hit by the virus. (Photo by Jae C. Hong/AP Photo)

In this Sunday, February 23, 2020, photo, sumo wrestlers wearing masks arrive at Shin Osaka railway station in Osaka, western Japan. A viral outbreak that began in China has infected more than 79,000 people globally. The World Health Organization has named the illness COVID-19, referring to its origin late last year and the coronavirus that causes it. (Photo by Kyodo News via AP Photo)