Joe Deedon, president of TAC ONE Consulting, demonstrates searching for a shooter in a middle school during an Active Shooter Response course offered by TAC ONE in Denver April 2, 2016. According to TAC ONE, the course, which is offered for the first time to concealed weapons permit carrying civilians, is designed at preparing people to effectively save lives prior to the arrival of law enforcement at an active shooter incident. (Photo by Rick Wilking/Reuters)

“Jessica”, a silicon sеx doll for sexual encounters lies on a bed at the “Bordoll” brothel on April 17, 2019 in Dortmund, Germany. Bordoll is Germany's first brothel to specialize in sеx dolls. It currently offers 13 female dolls and one male doll and will soon be expanding its female line-up. Schwarz says “sеx dolls are so popular because the client can do what he wants to and nobody complains”. (Photo by Lukas Schulze/Bongarts/Getty Images)

People walk under Australia's iconic landmark Harbour Bridge in Sydney on April 3, 2019, as heavy fog blankets the city. Low visibility due to heavy fog affected traffic in the city and caused flight delays at the Sydney airport. (Photo by Saeed Khan/AFP Photo)

A family take a souvenir picture next to giant male panda Xiao Liwu, who was born at the San Diego Zoo and will be repatriated to China with his mother Bai Yun, bringing an end to a 23-year-long panda research program in San Diego, California, U.S., April 18, 2019. (Photo by Mike Blake/Reuters)

In this April 3, 2019, photo, horses from Nepal cavalry rest in a stable after morning practice for Ghode Jatra festival in Kathmandu, Nepal. The “Ghode Jatra” is an annual horse festival celebrated on the Nepal Cavalry grounds in Kathmandu, which marks the defeat of a Hindu demon. (Photo by Niranjan Shrestha/AP Photo)

Flames rise from Notre Dame cathedral as it burns in Paris, Monday, April 15, 2019. Massive plumes of yellow brown smoke is filling the air above Notre Dame Cathedral and ash is falling on tourists and others around the island that marks the center of Paris. (Photo by Thibault Camus/AP Photo)

A woman wiper her eyes as she waits to pay her respects before the statues of late North Korean leaders Kim Il Sung and Kim Jong Il, as part of celebrations marking the anniversary of the birth of Kim Il Sung, known as the “Day of the Sun”, on Mansu hill in Pyongyang on April 15, 2019. (Photo by Ed Jones/AFP Photo)

People wear clothing to protect them from the heat while riding along a street in Hanoi, Vietnam, 24 April 2019. North and central Vietnam was recently affected by extreme hot weather, with the highest temperatures reaching over 40 degrees Celcius, according to the National Centre for Hydro-meteorological Forecasting. (Photo by Luong Thai Linh/EPA/EFE)