Desperate thirst: Drought is one of many problems that continually afflicts the northern African country of Ethiopia. Lack of water not only kills crops, meaning starvation, but also causes violent conflicts over scarce vital resources. Inadequate sanitation has made water-borne diseases the No. 1 cause of infant deaths in the country -- where 300,000 children under age 5 die every year. Here, a boy near the town of Moyale drinks from a muddy puddle.
