A girl poses at an entrance of her house next to a bomb dropped by the U.S. Air Force planes during the Vietnam War, in the village of Ban Napia in Xieng Khouang province, Laos September 3, 2016. From 1964 to 1973, U.S. warplanes dropped more than 270 million cluster munitions on Laos, one-third of which did not explode, according to the Lao National Regulatory Authority. (Photo by Jorge Silva/Reuters)

People look at a RoboThespian humanoid robot at the Tami Intelligence Technology stall at the WRC 2016 World Robot Conference in Beijing, China, October 21, 2016. The conference showcased China's burgeoning robot industry as the nation seeks to increase the use of robots in its manufacturing and service industries. (Photo by Thomas Peter/Reuters)

Parade Marshall Captain Gary Tomlin gives a command during a Remembrance Sunday parade through Fulham in West London, Britain November 8, 2009. Every year in November, villages, towns and cities across Britain honour those who have lost their lives in war on Remembrance Sunday. While Queen Elizabeth leads tributes at a national service of remembrance at The Cenotaph war memorial in central London, various neighbourhoods also hold their own local marches and memorials. (Photo by Kevin Coombs/Reuters)

A girl collects drinking water at Dala river outside Yangon, Myanmar March 3, 2016. Some 650 million people, or one in 10 of the world's population, have no access to safe water, putting them at risk of infectious diseases and premature death. Dirty water and poor sanitation can cause severe diarrhoeal diseases in children, killing 900 under-five a day across the world, according to United Nations estimates. (Photo by Soe Zeya Tun/Reuters)

WOOTTON, UNITED KINGDOM - APRIL 07: Hot air balloons prepare to depart from Lydden Hill race circuit near Canterbury to take part in mass crossing of the Channel on April 7, 2011 in Wootton, England. 51 balloonists of various nationalities from across Europe took off from Kent making for Calais, France at about 7am. It is the first time a Guinness World Record bid has been made for "the largest group of hot air balloons to make the Channel crossing". (Photo by Oli Scarff/Getty Images)

In this handout image provided by the National Oceanic and Atmospheric Administration (NOAA), model runs from the Center for Tsunami Research at the NOAA Pacific Marine Environmental Laboratory show the expected wave heights of the tsunami as it travels across the Pacific basin March 11, 2011. The largest wave heights are expected near the earthquake epicenter, off Japan. The wave will decrease in height as it travels across the deep Pacific but grow taller as it nears coastal areas. In general, as the energy of the wave decreases with distance, the near shore heights will also decrease (e.g., coastal Hawaii will not expect heights of that encountered in coastal Japan). (Photo by NOAA via Getty Images)

In this handout GOES satellite image provided by the National Oceanic and Atmospheric Administration (NOAA), Irene reaches hurricane strength as it moves across Puerto Rico towards Hispaniola August 22, 2011 in the Caribbean Sea. Irene, the first hurricane of the Atlantic storm season, brought torrential rains and winds to Puerto Rico, downing trees and powerlines and flooding streets. The expected path will bring Irene through the Bahamas and is likely to hit Florida and up the east coast of the U.S. (Photo by NOAA via Getty Images)

Tree trunks are seen in a forest on November 8, 2011 near Landau an der Isar, Germany. The German government is conducting a nationwide project to estimate the number, variety and geographic distribution of trees and forests in Germany, as well as their condition and health. Approximately a third of Germany is covered in woodlands, and though that territory has actually expanded since 1989, some analysts fear demand for wood will outstrip supply in coming years due to national growth in industry and bio-energy needs. (Photo by Johannes Simon/Getty Images)