A Palestinian girl and her brother sit in front of their house in southern Gaza Strip city of Khan Younis, on April 21, 2016. The 1.8 million Palestinian residents of the Gaza Strip are facing a growing water shortage. Currently, 90 percent of Gaza's main water supply is unfit for drinking and unsuitable even for agricultural use. The untreated sewage has infiltrated Gaza's groundwater, contaminating the water supply, which now contains high chloride and nitrate levels. [Photo/Xinhua]