A girl holds her brother in her arm as black smoke rises after an oil well set on fire in the center of al-Kayyara town to the south of Daesh terror organization-held Mosul in Iraq on October 25, 2016. The oil well in the center of al-Kayyara town, which was set alight by retreating Daesh militants in advance of the Iraqi army's takeover of the town on August 24, 2016 has still not entirely been put out. The raw petrol which is still alight is creating black clouds above the city. The residents and wildlife beneath this polluting smoke cloud may find their health at risk. The effects of the fire in the town center on unprotected civilians' health can easily be seen on the hands and faces of children playing on the street. (Photo by dris Okuducu/Anadolu Agency/Getty Images)

A view motorists have grown accustomed seeing, a military truck made by Oshkosh Corp. is taken for a test drive Thursday, April 11, 2013 in Oshkosh, Wis. Faced with deep cuts in U.S. military spending, and the end of the wars in Iraq and Afghanistan, Oshkosh Corp. is laying off 900 employees in its defense division based in Oshkosh. Approximately 700 hourly workers at the state's largest manufacturer will lose their jobs in mid-June, followed by approximately 200 salaried employees through July. (Photo by Mark Hoffman via The Journal Sentinel)

Max Gold, 20, of NYC, cruises on his skateboard as thousands gather on the National Mall for the March for Science on Saturday, April 22, 2017, in Washington, DC. Activists and scientists descend on the nation's capital to rally for environmental causes and government policies rooted in scientific research as part of the Earth Day and March for Science rallies. (Photo by Jahi Chikwendiu/The Washington Post)

Yang Juan, an employee at Goopal Group, takes a nap in her seat after lunch, in Beijing, China, April 21, 2016. Office workers sleeping on the job is a common sight in China, where a surplus of cheap labour can lead to downtime at work. But in China's technology sector, where business is growing faster than many start-up firms can hire new staff, workers burn the midnight oil to meet deadlines and compete with their rivals. Some companies provide sleeping areas and beds for workers to rest during late nights. (Photo by Jason Lee/Reuters)

In this April 28, 2015 file photo, heads of tuna on a cart are carried by a fish dealer after the day's auction at Tsukiji Wholesale Market in Tokyo. In one of the biggest of Japan's many New Year holiday rituals, early on Tuesday, January 5, 2016, Tokyo's Tsukiji market will auction off with much fanfare a huge, glistening tuna, likely destined for one of the big sushi chains. If all goes as planned, it will be the last such auction at 80-year-old Tsukiji. (Photo by Shuji Kajiyama/AP Photo)

A Palestinian beekeeper uses smoke to calm bees in the process of collecting honey at a farm in Rafah, in the southern Gaza Strip April 11, 2016. Rateb Samour sees 250 patients a day, whose complaints range from hair loss to cerebral palsy and cancer. He is not a doctor and has never worked in a hospital. Samour inherited the skill of bee-sting therapy from his father. From 2003 the agricultural engineer dedicated all his time to study and develop the alternative-medicine treatment of apitherapy, which uses bee-related products from honey, propolis – or bee glue used to build hives – to venom. (Photo by Suhaib Salem/Reuters)

A devotee with his body painted poses as he waits to perform during a ritual as part of the annual Shiva Gajan religious festival at Sona Palasi village, in West Bengal, India, April 11, 2016. Devotees offer sacrifices and perform acts of devotion during the festival in the hopes of winning the favour of Hindu god Shiva and ensuring the fulfillment of their wishes, and also to mark the end of the Bengali calendar year. (Photo by Rupak De Chowdhuri/Reuters)

Justin Nelzen, in red vest, joins others as they work to rescue up to 70 horses along Cypresswood Drive near Humble along Cypress Creek, Monday, April 18, 2016, in Houston. More than a foot of rain fell Monday in parts of Houston, submerging scores of subdivisions and several major interstate highways, forcing the closure of schools and knocking out power to thousands of residents who were urged to shelter in place. (Photo by Mark Mulligan/Houston Chronicle via AP Photo)