The National parks department hosts the 30th annual “All-Women Lifeguard Tournament” in Sandy Hook NJ. July 30, 2014. (Photo by Anthony Causi)

A woman holds a champagne bottle during New Year's celebrations in Bucharest, Romania, Wednesday, January 1, 2014. Tens of thousands of Romanians took to the streets of the Romanian capital to join parties and watch fireworks. (Photo by Vadim Ghirda/AP Photo)

Historical reenactor Troy Kotz poses with a mug of wassail in the parlor of the Guyon-Lake-Tysen House during the annual Candlelight Tour of Historic Richmond Town, Saturday, December 13, 2014, in the Staten Island borough of New York. The annual event lets visitors experience an authentic Victorian Christmas. This image was made using the TinType by Hipstamatic iPhone app. (Photo by Chad Rachman/New York Post)

A woman wearing a scarf to cover her face looks on as she waits for a passenger bus on a smoggy morning in New Delhi, India, November 8, 2017. The Great Smog of Delhi is an ongoing severe air-pollution event in New Delhi and adjoining areas in the National Capital Territory of India, in November 2017. Air pollution at this time peaked on both PM 2.5 and PM 10 levels. It has been reported as one of the worst levels of air quality in Delhi since 1999. (Photo by Saumya Khandelwal/Reuters)

The 2019 Nissan Altima sits covered before being presented at the New York Auto Show in the Manhattan borough of New York City, New York, U.S., March 28, 2018. (Photo by Brendan McDermid/Reuters)

Fireworks and light effects illuminate the night sky from the Taipei 101 skyscraper during New Year's Eve celebrations in Taipei, Taiwan, 01 January 2019. (Photo by Ritchie B. Tongo/EPA/EFE/Rex Features/Shutterstock)

A person dressed up as Damien Lavey of Monster Prom attends the 2019 New York Comic Con in New York City, New York, U.S., October 3, 2019. (Photo by Shannon Stapleton/Reuters)

The lightest material ever made has been produced by a team of scientists in China, a Chinese university announced.